Truly, especially for basic camping, very few models are going to stand out as special while still being affordable. If it's a used model, it boils down to thoroughly inspecting the trailer. Probably the most important thing to look for is water damage, which can show up in a lot of different ways. After that, look at the mechanical stuff; tires, brakes, bearings, etc. The appliances and fittings are mostly universal.
I remember starting out with these same questions years ago and errantly dismissing brands based on biased opinions from here. I ultimately bought a new "low end" unit from a "bashed brand" (for about the same $ as many other used units) and have been happily camping ever since. As it turns out, they still make 'em the way mine was made 10 years ago, which is the same way they made 'em 30 or 40 years before that.
You may want to focus more on desired features, versus desired brands.
