I struggled somewhat to get it with a totalgaming.net subscription, but I did succeed using a credit card. They'd also have accepted paypal and probably a major debit card would work too.
The absolutely critical thing that no-one mentions is that the email address you use to buy a totalgaming.net subscription must match the one for the stardock.net account you want to use the game on. Changing the addresses to match once you realise the problem is not good enough - you end up needing someone at Stardock to intervene.
Then there were technical problems with the installation. The new patch 1.02 was released while I was still downloading the earlier patch and that seemed to cause a problem. I was a bit put out to make two large downloads instead of getting the small patch download, but the real problem was the that the installation continued to get hung up very early on . I eventually thought it looked like a file locking problem and rebooted... and that did sort things out. So in the end I got the game and it's a fine piece of work. I also got an email from Stardock saying that they are working on arranging European distribution so we might one day see it in the shops.