When is the best time to buy a used class C RV

Depends on area. Here in Texas, the dealerships want to move rigs come end of year so they can have the latest year, and not 1-2 years back. Other places in the US might start cutting prices when fall hits because they know the rigs will be under snow after October.

I'm not much for trying to time the purchase. People can sell anytime for all kinds of reasons. It would seem like late fall might be good however snowbirds may be looking to buy. The whole process of finding a good used RV involves a lot of luck and informed sometimes lengthy searching. I would go ahead and look when I want one. personally I would look at Winebago and Itasca (made by Winebago). Good a quality as any and it narrows down the field. Old, longstanding company with good factory support.

"Best time" is hard to nail down. If you're buying on price, the best time is when others aren't standing in line waiting for a salesperson to help them. That would mean after the season is over and before the spring buyers start lining up.

That said there is also a consideration to be given for inventory. What good is a low price on an RV you don't want? We lucked out and found our ideal coach in early September. I also discovered that most RVs for sale at that time were the ones that no one wanted during the summer rush. Dealers let their stock dwindle so they don't have to pay flooring costs over the dead time of winter.

I agree that the best time to buy is when you find the RV you want. Figure out your budget and then start looking for what is in your budget. Our search took 2 years. I found that my original budget of $20K was too low for the quality and condition we desired. It wasn't until we got to a budget of $40K that we began to find rigs in good condition with the features we wanted. The dilemma this presented was that now we were knocking on the door of new entry level rigs. We decided that a well maintained (and well inspected) used higher end RV was best for us. That was hard for me because in my mind, $20K was a lot of money and I couldn't believe the garbage that people wanted that much for it.

As for brands, you will have to decide which ones fit your requirements. The only ones I didn't consider were Leprechauns because of leaking issues that were documented here at the time we were looking.

There aren't any particular years to avoid but there are considerations that will be dictated by your budget. Carbureted VS EFI. Early V10s VS later. 4 speed transmissions VS 5 speeds.

Major concerns should be condition and no leaks. When checking tire dates be sure to check the inside duals as I found several sellers who only replaced the 4 you could see and even turned the date codes to the inside of the dual so it was difficult to see. If they were that sneaky, what else did they hide?

As I said, it took us 2 years because I was very particular about what I wanted and it took some time for me to adjust my expectations as well as to discover other things we desired.

I would guess that after end of summer vacation season and before spring might be best. Try to buy a rig that is only five or less years old and one that you can get a loan for if needed. Almost any used rig needs six new tires if they are over five years old by date codes. Older tires may be blowout prone, They cost some $300+ apiece. I would buy a popular brand that is currently in business, i.e. Winnebago, Fleetwood, etc. I think that a 27 foot rig with a rear bedroom and RV queen bed is best for most adults with kids. Most newish rigs are based on Ford E-450 chassis and use standard brands appliances, AC, awnings ,etc. Slides are nice but can have electro-mechanical problems.
Have any used rig checked out by a pro truck mechanic and RV repair service and get written estimates for anything needed. Cooling system, brakes and tires and housebox batteries and electrical system and appliances are important items.
Lazy Daze and other higher end brands cost more and have higher resale values if maintained in good condition. Make sure that whatever you buy has a floor plan that you like. It's like shopping for a home.

The best time is just before closing time, just before fiscal year end, when the dealer really needs to make the sale.

Having a budget and your desired size and needs for your family, pets, or towing capacity makes life easier for those trying to help you.

Alas, as noted by Drew, the quality of a used RV depends more on how it was maintained and serviced, than anything else.

You want to get inside a potential rig and check for leaks. Look for discoloration around windows and doors, especially check the cab over window if the rig has one. Smell for mold and mildew. Check for soft spots.

Ask for proof the rig has regular service. Check the tires for date codes. RV/truck tires should be replaced about every 6 years no matter how good the tread looks. Find out if the rig was driven periodically or if it is a "driveway queen". It's not good for a RV to sit for long periods of time.

Check to see if the generator was maintained. Make sure all appliances work. Check the rig for delamination of the skin.

With respect to age, most would agree that an engine with modern fuel injection is much better than older engines with carbs.

Finally, there are some on the forum that recommend looking at rigs from rental companies since it is the companies vested interest to keep the units serviced and maintained.

Good Luck.

The best time is when you have the money and fine one you like at a price you're willing to pay. :)

For used RVs, the condition is IMHO a far more important consideration than the manufacturer. Obviously there are better makes and better model likes within a make, but a well-kept low-end motorhome will be a much better deal than an unmaintained high-end model. Besides this, many of the components are the same: the chassis are made by the same few companies, there are relatively few models and makes of appliances, the windows come from the same makers, etc.

Years to avoid is rather more dependent on details of the units you're looking at. For the most part, though, there aren't any recent years that should be avoided at all costs; the Ford (and Chevy, etc.) chassis are generally quite reliable if properly maintained, even the less desirable years.