You're going to be SO FAR money ahead if you just service/update your trailer. You can even bolt on new axles if that is what's going to make you comfortable. etrailer.com sells everything or you could probably even find a local trailer shop to do the work for you.
A new trailer is going to cost $4k+ -- that's a lot of repairs that you could make to your current trailer and parts are relatively cheap if you can do a minimal amount of wrenching yourself.
Former owner of a 1987 Supra Saltare. Current owner of a Malibu 23LSV.