Based on other info available (including the fact that Congress Park sold out in about a year, The Springs starting pre-sales 6 to 8 months before it opened, and, according to another thread I started, at least some portion of of the first 11 buildings built have sold), my best guess is:
75% of the existing 12 buildings sold, or
50% of the total 18 building resort
Also note, that if these estimates are anywhere near accurate, it would indicate that, despite all the posts about poor sales, sales are actually outpacing sales at OKW, BWV, VB, and HH compared to when they opened. Sales are even on pace with BCV, considering BCV sold out in a year, and Congress Park sold out in a year. (Yes, BCV has more rooms than Congress Park, and has a higher point schedule. But that is offset by the fact that Congress Park has 8 GV's while BCV has none, and 56 of BCV's rooms are dedicated studios or 1-br's, while Congress Park has none. The total points for BCV and Congress Park are within about 3% of each other.)