2. Get an idea of prices- When researching vehicles we got a good idea of how much things cost. Cost can really vary in the used market, but it seems as if most people have an idea of how much their vehicle is worth. Once you have a good idea, you have to decide a price you are willing to pay. You might have to adjust your want list depending on budget.
3. Learn about common problems- Learn about what could be wrong with what you are looking for. With a pop-up trailer, you want to know if there are any leaks or repairs to the canvas. The older ones with a storage trunk in front (particularly the Colemans) leaked. How bad is the leak? We looked at one that when the dude open the trunk about a gallon of rain water dumped in. He said, "Well that's never happened before!" LIE! The corner of the trunk had a squishy floor and the wood inside and the inside cabinets had water damage that went up about an inch from the floor. No thank you! Is the vehicle ready and safe to be towed? We always ask if it's smoke & cat free due to our allergies.
Find a forum or online group to help find out what to look for when you are purchasing, in particular with certain models.
4. Decide how far you are willing to travel to get what you want- If your wish list if flexible then you might luck out and get what you want locally, but you need to decide how far you will go. We had some flexibility with our time schedule so we looked as far as 5 hours from our home.
5. Stalk online sites- With the first 4 in mind, stalk CraigsList, Ebay, and sale listings. Both our last 2 pop-ups were found on CraigsList less than 30 minutes after they were listed. Pop-ups in particular sell very quickly. You've got to stalk and pounce! I found the cPro CraigsList app very helpful. I was able to set filters on my searches and double click to remove ones that didn't fit our desires. Then when I searched again just the new ones would pop. The downside of this app is that it seems to get new listings slower than on the computer.
6. Have money in hand- Good deals on vehicles disappear quickly. Have cash or quick access to cash on hand. Many sellers will work with the first to show up with money. You have cash with you (as opposed to a deposit or the need to return), the seller is often willing to bargain with you.
Make sure the listing is legit! Sometimes on CraigsList you will see the same vehicle (often at a very low price) listed on several CL locations. It's spam. Trying to get your info!
No vehicle is perfect! All RVs seem to have some issue or another. It will be hard to find something in mint condition! Some things can be easily fixed, others are deal breakers!
Fall is a great time of year to get a good deal on an RV! People don't want to pay storage fees over the winter and good deals can be found as there are fewer people willing to buy!
Take someone experienced with you! If you are new to RVs you might want to take a friend familiar with them with you to check it out. They would have a good idea of what to look for and how to test things out.
Make sure you ready to tow! If you are buying a trailer you need to be prepared to tow. Make sure you have the proper hitch, ball, electrical and anything else you might need.