American Express Membership Rewards - Paying to upgrade a corp card?

Does anyone know if you can pay the $250 fee to upgrade a green corp card to a gold, in order to gain the double airline miles? We are required to put all company travel on the corp card, but I'd like to get the gold benefits. Any info would be appreciated!

This is probably up to your company, not Amex. You probably can't just call up Amex and ask to have your card changed - IME that requires someone on a short list of authorized people within your company. Ask your accounting department and see what they say.

I know there are Gold Business cards, but are there Gold Corporate cards?

I know there are Gold Business cards, but are there Gold Corporate cards?
Absolutely. Platinum ones, too. But the benefits are a bit different (or they used to be), at least on the Platinum card.

It is definitely a question that AmEx will answer for you if you call. As noted above, some cards may not permit it but most will.

Is the $250 worth it for 2x miles on dollars spent with airlines? And is that benefit actually there? Those are questions you'd need to figure out, too.

I know there are Gold Business cards, but are there Gold Corporate cards?
Staring at one at the moment :) As sbm12 points out, there definitely are Platinum Corporate cards as well as I have that as an option at my company.