They are often in the fantasy section of local libraries so have a look in there. And used book shops are a great resource for anything out of print or rare just be prepared to browse a lot before you find them.

And some ebay sellers are happy to allow you to pay by other means such as credit card or cheque so long as the money arrives. Check the payment details on the bottom of the bid info to see what they will accept and even if they don't explicitly state they will take a cheque, maybe send them a message to ask if they will. If it is a certain sale they may well do.