Those I'm afraid are the rules on eBay, that any saw / bladed item require the member buying, to have a credit card on file, as that is the only proof eBay accept, to prove the person buying is over the age of 18, the age to buy those items.
The only workaround is to have a family member / friend who does have a credit card on their eBay account, to buy this item for you.
@geegee33.0174