Firstly i have no experience with this site, however i cannot find anywhere on that site where it states how many seeds are being sold.
If i'm missing it and it says 10 seeds then it's a saving of £12.99 from the popular 'attitude' bank.
So if you know for sure then it's worth trying, especially if others have bought from there before, but if i'm right and it doesn't state how many seeds i woud drop them an email to be on the safe side