Renting an RV was far more expensive than I thought it would be. Here are 15 costs to consider before you book.

At 20 feet in length, 12 feet in height, and 7.5 feet wide, the "compact RV" from Cruise America is the smallest motor home the rental company had.

Cruise America charged another $0.35 per mile driven. We drove 1,094 miles, which added another $382.90 to our rental charges.

While charging for mileage is standard, you'll want to take this into consideration if you're planning a long trip.

Cruise America, like most RV rental companies (though not all), also charges a generator fee: $8 per day or $3.50 an hour. Luckily, we only used it for a few hours on our first day since we were plugged into the electricity at campsites and bought a USB cigarette lighter charger for our phones while driving.

That fee only set us back $10.30.

However, it's worth noting that the generator runs on gasoline, so using it is a double whammy in terms of cost, as it also eats into your fuel.

We paid an optional "zero deductible" insurance fee of $14.95 a day; we weren't messing around as first-time motor-home drivers.

Until I got the bill, I didn't realize that this was on top of a mandatory $15.75 daily "supplemental liability" insurance fee.

Basically, the extra $14.95 upgraded us from a $1,500 deductible policy to a zero-deductible policy, meaning that instead of being responsible for any damage to the vehicle of up to $1,500, we had no financial responsibility for the RV getting damaged or stolen on our watch.

Since we were bringing clothes, towels, bedding, food, and water, my friend and I decided to splurge on the $110 kitchen set, or "Vehicle Provisioning Kit," that Cruise America offered, so we could keep luggage to a minimum.

While it allowed us to carry a whole lot less, the kitchen kit was somewhat insufficient, in my opinion, as it lacked bowls. Cruise America notes on its website that items included in the set may vary between locations, but personally I feel like bowls are pretty standard kitchen items, and if you're choosing not to pack certain things it would be helpful to know what you're going to get ahead of time.

If we'd had a car to drive to the rental place, I would have just packed my own cookware and saved the $110.

For another $60 per person, there's also a "Personal Kit" that includes bedding and towels. In the midst of a global pandemic, however, I preferred to bring my own sheets.

As part of the RV rental, we had to pay a "daily NJ surcharge."

Looking into this, I found that all motor vehicle rentals in New Jersey of 28 days or less require a $5 a day "domestic security fee," according to the New Jersey Treasury, which cost us another $20 total.

Colorado appears to be the only other state with such a surcharge, as Cruise America's website lists a $2 per day "Colorado road safety fee."

While Cruise America is transparent with these fees, they may come as a surprise to first-time RV renters, so it's worth doing your homework ahead of time.

Cruise America's website describes this environmental fee as "designed to offset a wide range of environmental expenses," including "costs associated with the proper disposal of oil, filters, tires, batteries, and shop waste."

While this added to our cost, it was a small price to pay and didn't bother us.

If you fail to completely empty your tanks before returning the car, you'll be charged an $85 dump fee.

There's also a cleaning fee of up to $150 if the vehicle isn't returned "in the same condition as it was received." Bypassing that was easy since, a) the RV wasn't really as clean as we would have liked when we got it, and b) we sanitized the hell out of it ourselves.

While prices vary between rental companies, these fees seem to be pretty standard.

RVs are subject to late fees just like those you might face if returning a rented car after the time it's due back. Our Cruise America location charged a late fee of $25 per hour if you returned your RV past 11 a.m.

While I got the deposit back, it's an upfront charge to keep in mind when budgeting. The deposit for our RV rental was $500.

Don't underestimate how much gas motor homes use — especially since items like the generator also use fuel.

We stopped to fill up four times over the course of 1,094 miles, and spent $235.42, which is almost $0.22 per mile driven.

We had to return the tank half full as received, otherwise, Cruise America would have charged $5.50 per gallon. The compact RV had a 40-gallon fuel tank, so it wouldn't have been cheap.

RVs use propane for their refrigerators, stoves, and hot water, so, depending on how long you're renting for, the number of hot showers you take, and how often you cook on the stove, you'll probably have to refill the propane tank at some point.

Refilling a 30-pound propane tank costs between $80 and $100 at Camping World, which sells camping gear and RVs at 120 locations across the US. And according to RV Blogger, which cited data from the US Energy Information Administration, refilling your propane tank at a refilling station can cost between $2.50 to $4 a gallon.

Since we only used the stove once and took one hot shower (we used the camping facilities or took cold showers), we didn't have to pay for propane.

While you could probably spend the night for free in a Walmart parking lot or "boondocking" — which means usually free camping in the RV community by not using water and electrical hookups provided at RV parks — as novices, we wanted the safety net of a campsite and friendly neighbors we might need to ask for help.

Campground costs depend on the amenities they offer (some have pools and ocean views) and their proximity to popular attractions, but, according to Camper Resort, they generally cost at least $45 a night and up for RVs.

In New York/New Jersey, the cost of a regular vehicle passing through the Lincoln Tunnel without an E-Z Pass is $16 — but a six-wheeled motor home can cost as much as $66, according to Port Authority NJ.

Thankfully, our RV was small, but we still ended up spending $21.50 on tolls driving from New Jersey to Maine and back. Due to COVID, however, many of the tolls we passed though said they'd send charges via mail, rather than have a person sitting in the toll booth, so the grand total might be higher.

While I congratulated myself on my foresight when I thought to pack dish soap, paper towels, and toilet paper, we ended up buying things like a lighter for the stove, a candle to be able to eat outside, hand soap, gallons of water, firewood, and a cigarette lighter charger, which also added up.

• Read more:
• 11 common struggles of living in a van you should consider before committing to the lifestyle
• A couple turned an old school bus into a gorgeous tiny home, and now they live in the 185-square-foot space full-time
• A nurse working to fight the coronavirus in California lives in a 75-square-foot van with his wife and 2 cats
• A couple quit their jobs and sold everything to live in a van. Now, they make money by building tiny homes on wheels for others.
• I spent a single night in a camper van with my husband and have a newfound appreciation for people who do it full-time

• This is an opinion column. The thoughts expressed are those of the author(s).