Well, what's the frame look like underneath?
Does it have enough frame, or was the roof and sides part of the structure?
how wide is the wife's car?
it might be worthwhile to make a pipe top trailer if it'll suit your needs
what's the title and tags gonna cost, or is that a bonus?
I can get a new pipe top trailer, new axles, new tires, for 2300 otd
If your horse trailer is too "wrong" to start with, you could easily be in 2k and have a worse trailer, or, if the trailer is suitable, you could have a nice finished trailer for 1k