To be fair, you're not at any point actual risk, all credit cards are protected against fraudulent activity so it would be your credit card provider taking the hit.
But it does sound like a scam. Quite a clever one, really. Give out cheap domain names, let people build a business around them, and then hold their business to ransom once the domain expires...
Which is why you should only ever go with reputable sellers in the first place

. Cheaper isn't always better.
But then...
I have always found "namecheap" to be one of the best priced and also on the level.