As the title says, what are your thoughts about buying second hand mining rigs or GPUs. I've checked on Ebay and lots of options are there to get cheap -or at least it seems to be, mining rigs or nvidia GPUs and  even antminers for altcoints.

I know that mining Bitcoin nowadays is not very profitable in the short run due to costs involved to get proper mining equipment. Getting  second hand hardwares might be an option.

I've also listed some almost-new chinese GPUs.
Please post your reasons why it is or it is not a good option.