Are you sure that if in Germany you buy 5,000 in bitcoins and after some time you cashout 50,000 you have 0% to pay? No capital gains tax? No other tax? I don't think is that easy.
If you hold the coins for more than 1 year, there is no capital gains tax in Germany.
http://arstechnica.com/tech-policy/2013/08/germany-recognizes-bitcoin-as-a-private-money-subject-to-capital-gains-tax/(note the subtext on the title). "The Ministry also clarified that if a German taxpayer holds bitcoins for more than a year, she is exempt from paying the 25 percent capital gains tax." Germany was actually the first country I heard announce this, so it's been on the list for awhile now.
-Burger-