That's vile.

Saw a few consoles like that back in my Funcoland days. Always equal parts shocking, disgusting and insulting that somebody would even attempt to sell something in that condition. Needless to say I wouldn't even consider buying one. (Though, no fault to you for not noticing it until it was too late.)

I have no interest in touching something that insects have lived, bred and shat in, and I hope you've considered the likleyhood that there could still be eggs in there that could hatch and infest your own home.