You can get really good deals from GC used, but their descriptions are not always accurate. I have bought quite a bit of used gear from them. Some needed nothing, some needed minor repairs, and some was beyond economical repair.
Confirming the operational status of the amp should be done soon enough to allow you to take advantage of their generous return policy. Even better if you have a local GC, so you can avoid the hassle of shipping.
Shipping from GC Used is often surprisingly cheap, but how well they pack gear varies wildly. I bought a used 1960BX from them and it was packed in a huge box filled with bubble wrap and shipped freight on a pallet. An 18 wheeler backed up to my drive way and lowered the pallet with a lift gate. Another purchase involved a near mint 1987 Ampeg SVT. This was packed in a flimsy box with really fragile bubble wrap. The amp arrived face down with pretty much all of the bubbles popped. The mid control knob was snapped off and the front panel was marred a bit. The local GC tried to get me to do a return. But I talked them into fixing the damage. I had to tell them where to buy the part though. A week after getting the amp back, a filter cap failed in the power supply. I did a full cap job myself as I knew they would insist on a return.
