At a budget of $10,000 you will NOT be getting anything close to recent vintage so, you will be seeing OLD, "inexpensive" trailers (which generally do NOT 'hold up" well). Molded fiberglass trailers DO hold up better than "regular" trailers BUT, also hold more of their value (which equals prices beyond your announced budget). I would STRONGLY recommend that you stay AWAY FROM old, "regular" trailers. There's just too much that can be (and usually is) wrong. Unless you're VERY handy and, like VERY involved projects. my recommendation would be to wait until you can afford to spend more. By all means, keep looking. As you've already discovered, there's a LOT of garbage out there but, you may luck out and, be in the right place at the right time.
Something that will GREATLY help you would be to attend an RV Boot Camp. AT RVBC you, along with ~ 200 other newbies, will have all the systems found on a modern RV explained and Demystified. Many attendees with come in their RVs (you can drive in and stay at a local motel or camping cabin). You and your S.O. will have the opportunity to network with many RVers some of whom, will be looking to "graduate" to a different RV (especially when the RVBC is over) and, want to find a buyer for their old RV. The Escapees run an EXCELLENT RVBC (Escapees may have invented the concept of RVBC). Other groups now offer their own versions of this important training (calling their products by different names). Escapees RVBC and FMCA's "RV Basics" runs over two to two and a half days. RVSEF and RV~Dreams run their classes over a week (more social activities). RVBC graduates are safer RVers and, smarter RV buyers. Some insurance companies offer discounts to RVBC graduates.