I've had no problems with paying Legalsounds upfront with a credit card. However if you have doubts use a card with little money in it and opt to pay £10 at a time. £10 goes a flair way at 9 US cents per track.
the Russian site was legit it was not a scam but it went against the legal copy write thing like limewire and the rest did so was closed down but it has popped up as another name but don't know it
The Russian site in the news in 2007 was allofmp3.com - they were selling songs for a fraction of ITunes prices. They said they were paying royalties, but they still got shut down.