Instructive Hand Combination Quesiton

[theBruiser500]

Okay here is the situation, 4 handed touranment, winner take all. UTG with A9o 1900 stack everyone has me covered, trying to figure out if it's profitable to flip cards face up and push. This is what I have so far:

1326 total hand combinations
22-88, A9 6 combos of each, 48 combos total
AK-AT 48 combos
KK-TT 24 combos
99, AA 6 combos

So the first 48 combos are all a wash let's say, the expectation is 0 so ignore them. Then there are 78 combos that have me beaten about 3:1. Then there are 1326-42-78 = 1206 combos that will fold when they see my hand. So against one opponet this is:

(1206/1326 * 300) + (42/1326 * 0) + (78/1327 * -900) = 220
(-900 is gotten by, [.75*-1900 + .25*2100] = -900)

Is that right so far? I did .25*2100 btw because if button calls it's 2200 in pot, SB calls it's 2100, BB calls it's 2000. How do you do this against 3 different opponents though?