already bought the game, so it will be another $40, which can't afford at this time. Plus, the only time my wife will really play this game is when we play together, which will probably only be 1 time per week for a few hours, so $40 for that little use seems little much.
In that case you should probably wait for a sale. You could also buy the GOG version for about 28€ (depends on where you live) which works together with the Steam version in co-op via LAN.
