Stake your 8K (2000 packs) into SPS and you'll earn quite a few vouchers, I think around 5x per day. Over 30 days you'll get over 100 vouchers and you can at least get the 100 pack special that guarantees you a promo. SPS is at 0.48 right now so you'll get 16666, and at 84% APR that the pools at right now you'll get approx 1166 bonus SPS ($559) that will cover the $400 (-10%? I forget) you'll need to buy your 100 packs and leave you with marketplace money. Don't worry, you're in a better position than most :)