One book being sold on Amazon, thinking of selling elsewhere

Hello, I have been selling one book on Amazon since 2007. The last few months I have been getting messages that the price is too high. Dealt with that, it started again yesterday. Then I got a message about the account not being active enough and I had to start from scratch again today. I have it sorted out. But this is one book I’m selling it is old, thinking of selling it on a wiki site, what is the best options for payment it someone clicks buy book? I’m very old school thank you little chickadees in advance.