you should upgrade to a used or new 12900k with DDR4 since its still cheaper than dd5 even if it is up. then get a used 3080ti with 12gb. youll be able to do proper h.265 decode/encode with that for up to 4k (unfortuantly not 8k but hey no one really has that yet)
seriously. given how sellers and creators have had their accounts locked and sometimes not gotten their crap back. it would be unwise. if your going to buy crypto on paypal make sure they let you forward it to your own wallet.