Yes there but it's a fairly large one so that you never runs out of disk space if you put custom maps on you server. Do be specific, there's a 20GB limit, if you go over the server will be shut down and you will loose the credit associated with this server (if you have put any). This limit is purely to prevent abuse because 20GB is pretty much enormous for custom maps :)
We should have enough servers for that to never happen. It might be a temporarly shortage so keep trying in a few minutes.
We use Paypal so you can pay using credit card (without a PayPal account) or using your PayPal account (bank transfer or anything else PayPal accepts).
Yes, if we can, we will ! But please tell us what games you would like to see supported by ODGS, that way we will prioritize our development effort.
And one more thing : please don't ask us to add games we can't support :