Does costco except gift cards other than Costco's?

Visa gift cards.

Only Costco gift cards at the store. The on-line store accepts other credit cards. Such as Master Card, Amex

Probably not. You must call.

No

I Don't know.

No just credit/debit cards and Costco gift cards

Only Visa gift cards. The card must show the Visa logo

You can probably use a Visa or MasterCard gift card, you will have to check first, but you will definitely need a membership card if you use other than Costco gift card.

Visa cards and Costco cards only