Thanks for these!
I'll be at the IC Bangkok in April (after my Expedia $3 Tokyo Hilton stay) and they've already confirmed my upgrade to an Ambassador Suite ^
I'm spending two nights. First night lowest rate was ~ $110, the highest available prepaid rate was a club suite for $220. I booked that and applied a free weekend night cert for the second night. So $220 for the 2 nights. Then the property confirmed me into an Ambassador suite, which is advertised at $750.