Visa or AMEX gift cards carry hefty fee at purchase, plus fees to use (if certain conditions are triggered). Personally I think it is a complete rip-off just by the cursory look at it so never spend any time to really look into that.

Store-specific gift cards normally dont carry fee and many now do not expire, but you still need to double-check. If you dine out often, you may want to explore the restaurants you often go to, offer any type of gift vouchers, for example.

The $750 is easily to be met if you order the US Mint coins. There is a long-running thread in Miles Buzz forum - go check it out.