If you have the money you probably need to transfer the money to an escrow account. Even if you are loaded you probably wouldn’t have a credit card with a million dollar limit.
The escrow agent calls the other party to tell them that the money is on the account. The domain holder transfer the domain rights to you then you call the agent to tell them that the deal has been concluded and they will send the money to the seller.
If you lie that you didn’t receive the domain rights you won’t get the money back since both parties tell a difference story. The money stays on the escrow account and the case will go to court or into arbitration.
No. Actually they don't. Nor would they use a credit card to make these kinds of transactions because the fees are too high to the buyer. Or more correct, the buyer would tack on a surcharge to use a credit card. Might use a credit card to put down a deposit but that is about it.
Yeah, actually they do. I've been working for a wealth management bank in Luxembourg for several years, and we do have unlimited credit cards. Technically they have a 999,999,999 EUR limit since there needs to be something, but good luck spending this much anyway.
Also, credit card fees outside of the US are rather tame in comparison, and usually even capped. I've seen someone buy a Bentley worth >1M with his Visa.