I bought a Case DX29 about 2 1/2 years ago at A-plan pricing -- dealer cost. I had them add a grapple and the plumbing to go with it plus a set of rear hydraulic valves. My price new was less than your quote, but as noted, that cab is worth at least $3500-$4000 used and I would put the snowblower above $1000, although I wouldn't want one that badly when a blade will do. I have just over 200 hours on my tractor.
If you need a cab and will never need to have a short tractor to clear garage doors and such, that sounds like a good price. Spend one winter clearing a lot of snow on cold windy days and you will be very happy to have the cab on there. Spend one summer doing a lot mowing on hot sunny days and you will be very happy to have the cab. I live in the woods on the lee of a hill, so neither of the above applies and I'm pretty happy without the cab. Besides, I would have ripped it apart 20 or 30 times by now going into the barn, the garage, or under branches. It's bad enough when I forget to lower the ROPS!