if I want to purchase a matched song shouldn't it be available in the iTunes store??

I'm not fully understanding iTunes match.. I have songs in my library that are matched but some of them I want to purchase from the iTunes store. If they are matched that should mean that they are available in the iTunes store because iTunes is seeing them and re-downloading them to my library. However, when I try to find the song in the store to purchase it's not there...

Wondering if anyone has any insight to this?

Thxs