So the answer for the OP would be something along the lines of what I am doing and that is waiting for the gamma version to come out and then decide which card to go for, for a number of reasons
1) by then the game might be optimised so that an upgrade isn't really needed
2) Newer cards will be out and the upgrade choice appears again so may prefer a newer card rather than one of these
3) Either of these cards (780Ti or R9 290x) should suffice for a long time to come but will be cheaper by then
4) Hopefully you will have saved up a bit extra cash so that price isn't such a big factor
1) by then the game might be optimised so that an upgrade isn't really needed
2) Newer cards will be out and the upgrade choice appears again so may prefer a newer card rather than one of these
3) Either of these cards (780Ti or R9 290x) should suffice for a long time to come but will be cheaper by then
4) Hopefully you will have saved up a bit extra cash so that price isn't such a big factor