Well you can get your toes done a few times! Sometimes they also offer other services so you might not have to get your nails done. Still sweet that he thought about you even though it isn't something you normally would want.
Another idea would be to go into the nail salon and see if you can get a refund. Sometimes you can get refunds on gift cards. You might take a bit of a loss but then you could get some cash too. And is it a plastic card gift card or a paper certificate on?. A lot of times with the paper ones, after you use it once they give you the difference back in cash. So get your toes done. Show them off to the hubby and make him happy. Then use the cash as you please! New fabric? :)