This is my first time posting in this gameshare thread, so i hope I am doing this right as far as format goes.
I have: $10 off an order from gamestop promotional code
I want: all Borderlands 2 DLCs (season pass, extra characters, etc...)
Sounds more like a trade the way you have listed.
Gameshare is a group setting up downloads they are interested in and splitting the cost with 2 resells and 2 phantoms. There are also groups that have been set up before and resells from these on the market occasionally.
There may be some Borderlands DCL groups willing to let you join in an open spot. It will cost cash though not a trade.
Hope this helps, new to the sharing myself.