if you really aiming to win you will do your own research those who buy tips are more prone in losing their money its not because the tipster will provide wrong pick but you will continuously relied from those people, better yet do your own research and use those tools that has been provided to analyze your own pick.
I agree, when you pay for predictions your profits go down at the same time only if you win but if you lose it's like losing a bet twice. It's really not advisable to buy picks unless you have money to lose. Some users i've been watching make their own model to determine who's the winning team.