How much is worth Football Manager 2014 gift?

Hi. I have 3 copies of FM 2014 that I want to get rid of. I want to ask you guys some questions:

1) What was the price before it was removed from the store?

2) How many TF2/CSGO Keys should I ask for each copy? (I think I bought them for about 6 TF2 keys)

3) As time goes by, the value of this game remains the same, is worther or less worth?

Thanks.