Any really cheap laptops good for minecraft?

No, you're going to need a bit more money if you want to buy a brand new laptop that can support MC on medium settings. It takes about $600-$700 to get a brand new work laptop. I recommend going on eBay or Craigslist and looking for cheap laptops. Every once in a while, there's going to be a really good, cheap computer.

I found this on Craigslist: http://boston.craigslist.org/gbs/sys/4218051553.html Should run on at least medium, if the i5 is a 3rd gen. Try looking for APU based computers, as those run the best for graphic intensive programs such as minecraft.

At that price point, you'll need a bit of a work around. I would suggest you get a chromebook with intel processor (recommended the ACER C720) and install Ubuntu on it. Then you can install Minecraft on Ubuntu as you would like. The Acer C720 is currently selling for 199$ on Amazon. Yeah 199$. It should be able to play Minecraft at an acceptable frame-rate. More info from the link below