Originally Posted by MSPeconomist

I'm confused about the OP offering $1500-2000 at check in to get an upgrade. Do you mean to offer to pay more or are you planning to give the front desk agent an enormous tip/bribe?

I would think it would be better to try to negotiate an upgrade in advance (for money) through the hotel's rooms manager or front desk manager, but this will be expensive, even in low season. Personally, I would find it unseemly, especially in a hotel of this sort, to be begging or bartering in the lobby upon arrival.