Just bid.
EBay makes no real difference between buyers and sellers in terms of accounts.
Most experienced sellers will say to use different accounts for buying and selling, but that is category-specific.
I sell mostly philatelic material on this account. I have no problem buying dresses and purses with it.
There could be a problem if I were buying stamps with this account and then re-selling them on the same account.
If you do want to set up a new account for buying, you will need a different credit card number but you can continue to use the same Paypal account if you wish.