Can companies really do this?

I recently heard that no establishment is allowed to refuse your credit card as payment when you spend under their minimum limit. So if I go out to a burger joint for lunch and the bill is $4.32, they would tell me that they don't accept credit cards for under $5.00. Is it legal for them to do so?

If you need to put fast food on your credit card, then perhaps you don't need the food that badly.

Yes, they can put limits on prices. This is because they are charged for the transaction through their merchant account and at 4.32, it is hardly worth it for them to process it, because they will less than likely break even on that transaction. More likely, it would be a wash.

Pay with cash at fast food joints. Why pay 20% interest on a burger?

Firms can set minimum allowable charges. For small charges the charge is too expensive due to the base fee charged to the merchant--e.g. 45 cents plus 3%.

Large firms like McDonalds have special arrangements but most firms cannot get the charges reduced like that.