Or you can buy knockoffs for $40 on plenty of Japanese sites.
The question is how much is the signature worth? If you live in Orange County you can meet Selanne pretty easily at youth hockey tournaments he's involved with and he is a very nice and approachable guy who will sign anything. If you don't then obviously getting a signature will be more difficult.
From what I've seen adding a signature to a jersey will add about $50-$100 to its price tag. But what's the "friend" price? I think $125-$175US is a fair price depending on condition.