Question about upgrades

Hey I have a couple of questions about account upgrades.First where do upgrade sellers get there upgrades and If I got a prepaid cc could I start selling upgrades by buying the upgrade after the trade?Example:Customer A wants to buy a upgrade from me. He pays me and I go onto his account and buy the upgrade for him. Is this allowed?
Thanks in Advance

 

hmmm some people buy gamecards for online and i think they get % off sometimes, yes you can do that they can pay you and you will upgrade their accounts ...but make sure its not a continuos membership if you use your cc

 

Thanks for the input hold

 

Depends on the seller and where they live. Some do upgrades via sms meaning you type in their phone number and they receive a text and have to confirm it to give you membership ( which I feel is the safest way to upgrade) Some take advantage of currency exchange rates when buying upgrades.