First and always, what will you be towing with. Some suv's, such as Subaru's, have surprisingly low towing capacity. Look in the owners manual for your vehicle for correct numbers
And: A lot of new FGRV lookers tend to think that "affordable" isn't in our vocabulary. An FGRV will cost most than a comparable, or even bigger, stick built trailer, but it will usually be in better condition and will remain so, as well as hold it's value better, for many, many years.
As the oldest of the FGRV's still in use are now only about 45 years old so we still have no idea how long one will last.
About the best sites for FGRV's
for sale are Craigslist.com for your surrounding areas and <<<fiberglass-rv-4sale.com>>>
Good Luck Hunting