Buying Bitcoin

I use a few different exchanges to purchase Bitcoin. I'm only buying fractions and I want to buy it at the closest to actual market (yes I know about limit buys). After some research and using different platforms, I found the strangest place to buy Bitcoin at less than market. Its cash app. No I'm not suggesting it but what I am here for is to ask , am I seeing this correctly? Does or has anybody used their platform to purchase Bitcoin? I have not tried to sell any but it appears that the sell point is market as well. Just wondering. Didn't know where to post this either.