Ultimately the GA is your call, but ATC were probably trying to squeeze you in due to traffic conditions at the time. Not unusual at larger airports for ATC to give you a VERY late landing clearance - its really all down to how comfortable you are with accepting it. Remember you can go around at any height you want, just as long as you deem it safe to do so. I have gone around at 50 feet or less, which is really no big deal, although lots of variables come into this, like wx, wind, obstacles etc.
Remember that large a/c go around from 200' agl on an ILS, and in reality they can actually dip below this in the process...