Before you buy that, contact a local dealer - they might have a floor model or even a new one for a comparable price. Never know!
I now have the 4500d - similar to the one you are looking at.
My only gripe is that I hate the auto threader. I wish it wasn't there but it is what it is. Once it does decide to thread, it's good to go. I have to do a weird ritual each time I change the thread.. foot down, needle down, needle up, foot up then do the auto threader lol. It's funny that I have an a.d.d. machine but it works great once I have her threaded.
Having said that mine doesn't get a lot of use either. I have been too busy with my business to do much for fun and I won't do embroidery for others as I stress out too much if I don't do it right... or the machine sucks in a shirt or something. It is just too stressful for me so I don't do it at all.
I think you will be very happy with the Brother 4000.