One important part of your calculation is missing. How many chips do you have? I don't think you can just look at pot odds
. I think you also have to take into account how many chips you have, how many chips your opponent has, what have been his/her betting tendencies, etc. If it is early in a tourney and you only have 4,000 chips, you are basically risking one-eighth of your stack to call. Then you have to factor in what would happen with the turn bet. Has your opponent been aggressive? Do you have reason to believe he/she will shove the turn or at least up the bet to maybe 1,000? Is it worth risking a significant portion of your stack to chase a straight?
On the other hand, if you have 10,000 chips, you can float 500 out there just to see what happens.