Good for you bro! I just started playing 2 months ago and I have also doubled my investment.

Buying as many packs as you can is a good plan, but I think you can maximize the bonus by buying in bulk. For example by buying 100 packs at the same time can you can get 10 extra packs! But I guess you already know this but as you have said you've already made too much. HAHA I wish I can also be like that! If you have some spare voucher too you can send it too me!! hahaha I was aiming for 100 vouchers for the extra 10 packs but with my SPS I can only get 70.

Selling the vouchers is not a bad idea either. I think it really depends on your long term plans. If you are in for the long term then buying the cards and possibilty of acquiring a promo cards is a good plan.

Thank you for the comment and upvote bro! Really appreciate it and if you have any unused card you can send the to me! hahaha just kidding! IGN : cryptoche hahaha THANKS AGAIN bro!