If I were you I'd at least investigate repair and upgrade of my existing trailer before looking at a new one.
I spent a little less than the current bid of $1400+ upgrading my existing '01 Mac trailer, so it will be interesting to see what this one goes for eventually. My guess is well over $2K. My upgrade iincluded disc brakes on all four wheels; the offered trailer has only two wheel brakes.
I lost track, but I also put around 15-25 hours of my own labor into mine, including repainting. 'Course our own labor is free, right?
Mine is used in salt water infrequently, so it was in excellent shape when I started the upgrade. A new aluminum trailer is definitely an additional positive consideration if your use is primarily salt water.
The new one will still have to be modified, perhpaps substantially, to fit the Mac even close to the way the factory trailer does.
If you don't live close enough to pick it up yourself, my guess is delivery (to say, someplace like NH) could run at least $1000 or more, unless you can buddy up with a number of others buying the same trailer and split the shipping several ways. I'm sure that's why Mac doesn't bother offering them. If you need a new trailer, you're probably not going to be happy with a stock model anyway, and it's cheaper to get one custom made somewhere close to your home than to buy a cheaper factory version and then pay almost what it's worth again to have it shipped. I believe Champion, one of the largest web trailer sales outfits, doesn't do shipping of completed trailers at all; you're on your own.
I often wonder why manufacturers put brand new items on eBay rather than simply selling them directly over the web. Do they expect it be be bid for more than it's actually worth, or is there some not so obvious financial incentive, like avoiding service and warranty considerations, or what?