Hello,
1. If you are going to use 2 receivers, you need no dual-login, you will need second account for 2nd receiver.
2. Only if your new receiver has 2 tuners onboard, you will need dual-login. According to the rules of the server, you have to wait until your subscription is finished and buy dual-login. But, if you need it urgently, you may send e-mail to Moderator (moderator at cardsharing.cc) with request to cancel your current subscription. The remaining balance will be deposited to your account, and you will be able to buy dual-login.