There are heaps and heaps of words in English and Spanish that mean more than one thing. We are inclined to throw up our hands in horror when we come across this phenomenon in Spanish, and yet we speak a language full of ambiguities. It’s partly because of this that we can make jokes. Just think of “fork handles” and “saw tips”! A very common example of this is the word “light”. We can “light a cigarette” “turn on the light” have a “light colour” and also “a light snack”.
Anyway, something similar happens in Spanish with “cuesta”. It is a form of the verb “costar” (to cost) and can refer to prices of things, but is also used to express the difficulty of something. You can say “me cuesta entender español” (it costs me, that is, I find it difficult, to understand Spanish.)
At one time I belonged to a walking group in the north of Spain and every time we started panting as we walked up a hill (una cuesta), someone would comment: “cuesta la cuesta” (it’s difficult to walk up the hill).