yes, it is 0.1BTC but the winner will have it for much less. You think a lottery where can win big prices give it also for free?
Also shipping cost money.

I can lower the amount but have to add more slots and then it will take too long i guess before the draw.

That some are scared for scam i understand but then dot gamble and not every newbie is a scammer. everyone started here as a newbie.