Re: What to look for in an used trailer?
I guess it depends on what you consider the obvious.
Strap in good condition?
Winch in working condition?
coupler working freely?
all lights in working order?
wheel bearings free and greased?
Jack working?
bunks in good shape?
Rollers lubricated?
If it has brakes, do they work?
Condition of tires and tire pressure?
Other than these, I guess I don't think there's anything beyond the obvious
In most cases, I'd guess a marina will not sell a dangerous trailer without informing you of what it needs. If everything works, sounds like $400 is a good deal to me!
Good luck!