World Version Number on Marketplace

Buying survival spawn worlds on the marketplace and playing around in them is one of the things I like to do in Minecraft. However, when I find a world with builds I'd like to actually play in for any length of time I find out the world version number is significantly lower than the current release of the game. I would like to spelunk in caves and cliffs, I would like to have a vertical axis lower than 0, but I can't because a lot of these marketplace worlds are templated off old versions of the game. 

The version of the game the marketplace world is built on should be listed in the marketplace sales blurb. I'm tired of buying survival spawn worlds but only being able to play a fraction of the game. Please list the world version number in the marketplace or have a setting where I can manually update the marketplace world to current content.