Echinocactus horizonthalonius
I had been considering buying this same species of cactus (for 7x the price in a 6″ pot) a few weeks back but am glad I waited because… Well, 7x cheaper is always a good thing!
It is tiny though, only a 2″ pot but it does look a little healthier (It is almost June now though, rather than late March so that might have something to do with that) and space is limited so… Yay! New cactus, low price. May have to wait a few years to see flowers but that’s alright.
All Andrew's Plants 
I love that plant! This is kind of weird but…I killed one once, it imploded and turned to mush. I picked off all the spines because I thought they were so cool. I still have them. They look like spiders.
They are some fantastic spines, I love the washboard texture on them too.