Where can you buy Gmod really cheap

If you are truly, as you say, "broke as [censored by me]", wait until December for the Christmas Sale. There's a high chance Garry's Mod will go on sale then. There will likely be minor sales in the coming weeks/months, so keep an eye out in case Garry's Mod goes on sale. Event sales are your best bet, Garry's mod went on sale for just over 2 Canadian Dollars at one point, however, that was the Canadian Price, and since I'm a Canadian, that price applied to me, so I bought 3 copies of it.