Victor,
Not sure why Betfair won't accept Netherlands players. But anyway all the major sports sites are offering 5 as the price for Spain. Betfair has 5.2. That's actually the same price as 5, since that extra 0.2 will be taken from you in commission. The 5% commission isn't taken on matched bets, it's taken from the winner's net profit. On bets like this (a fairly long-odds popular line which has to be priced competitively) Betfair will never have better prices than normal sports betting sites.
Just sign up to a reasonably large sports betting site and bet it there. There's a list of sites offering the bet
here. (Note that when it says "4" for the odds, it really means "4 to 1", i.e. 5 in European odds. You can confirm this by checking the line on the site. I was having trouble finding the line on bet365 btw so make sure you can find the line on a site before signing up). Getting money on one of those sites wouldn't be any more of a hassle than getting it on Betfair surely?
Last edited by ChrisV; 03-10-2010 at 09:29 PM.