The first passage sounds best, but still has errors,. Here is the corrected version. "The head of Jesus has been found recently. It's up for auction now. Wanna bet?" "Jesus' head has recently been found. It's up for auction now. Wanna bet?" Please be aware that in written English we don't use slang, so "wanna" must be written as "want to", but to make the question both complete and grammatically correct we would ask, "Would you like to bet on it?"