ANYWAY, my reaction aside, there's a simple solution that DOESN'T COST $20. Well, hold on, in case you're skimming through this without really reading it.
DOESN'T COST $20!!!!
Unless you know, you wanna tip me or something. :3
All you have to do is devote 711MB of your valuable internet to this one zip folder, put what's IN the zip folder in the right spot in your Garry's Mod folder, and it'll be like stepping into a dream world where you HAD $20 TO WASTE!!!
This link is the one that worked for me.
http://www.moddb.com/mods/sg-stargate-maps/downloads/css-content-for-gmod
If that link does not work, here's an alternative link that may have a solution.
http://www.google.com.au/
GOOD LUCK AND STAY FANCY.
In order to establish that I'm not a spambot or something, I'd like to take this moment to say "Cheerio" as well.