It cost me an arm and a leg this phrase means what?

An arm and a leg actually means extremely or excessively expensive, even exorbitantly expensive. This idiom is generally used to describe something in terms of its cost, when the cost is extremely high, and almost not affordable and you have to part with a large portion of your resources to be able to afford it.

this is what showed up when i googled it

It means really like really expensive

Ur welcome