I want to make sure I understand this:
1) You have 7k total, you have 5k left after paying the BB of 2k.
2) All but the big stack have gone in for a total of 15k +2k (your BB)=17k in the pot.
3) It will cost you 3k in chips to win 17k. You will still have 2k left after calling. (I think you wanted the situation to be that you had to go all in to call in this situation so you should only have 3k left after paying the BB.)
1) You lose. You are still in 3rd position (in money) and have only 2k left in chips and are very short stacked.
2) You win. You are chip leader with 22k in chips and have a decent chance to win the tournament outright.
3 You fold. You are in 3rd place with 5k in chips and are still short stacked and in 3rd positions.
I don't see much difference between option 1 and 3. Pot odds
are there for you to call with just about anything. I throw my 3k in chips in and lets see the flop.
If you want the decision to be based that you had to go all in to call. I would still call, if 3 of you go out with the exact same chip count, you should split 3rd place 3 ways(gentlemanly thing to do). You should still get $33 back, probably close to your entry fee. If you won the hand, you would be tied for the big stack and have a good chance to make 2nd or 1st.