I agree with Tyler that the kart in the pics is sweet. but I really do not think that Cyberdork is going to be able to even stay anywhere close to his budget with the Sidewinder. I think to stay on budget you are really going to have be creative.
here are some ideas-
1. first develop a plan or buy some plans online
2. develop a preliminary parts list and then try to get as much stuff used or free that you can. I have seen people give away pretty decent kart motors on Craigslist, and even on one occasion a running motorcycle engine.
3. find a good auto salvage and a decent motorcycle salvage-for instance you could get brake calipers, and actuators off of a motorcycle and then do like Kibble and get a brake master cylinder off of a Car. You could also prob even find stuff to fab your suspension parts at a salvage. Like motorcycle coil over shocks. or even maybe VW old style bug half shafts (I think these could possibly work)
4. Find a metal supplier that also has a scrap pile in addition to their new metal. Old metal after being sand blasted tends to look like new metal. Just be sure to ask how they price their used metal before digging out what you want. Sometimes buying scrap metal by the pound can cost more than new metal.
5. try posting a wanted add on Craigslist asking for leftover metal, motors, shocks etc. Sometimes when people hear what you are doing they will bend over backwards to try and help you out. I would much rather see kids or in your case a young adult building a kart and learning valuable skills like welding and wrenching, and project management than out getting in trouble. I mean for instance look at guys like Tyler and Kenny who can weld and wrench with the best of them. They will probably end up being our future engineers one day. That is awesome in my opinion.
6. get family involved to help you buy parts and hopefully tools and maybe even teach you some of the skills you need to build.
and last of this windy answer, I have posted some pics of a kart without suspension but with a pretty decent roll cage. I am planning to add a swing arm to the rear soon and double A arms to the front. I have already built my front end with double A arms, coil overs, a mini sand rail rack and pinion, heavy duty stepped spindles, and sealed ball joints. Now all I have to do is cut and mod the front end of the kart to accept the new front end I built.
good luck to you, hopefully some of us from the forum can help you if anything from encouragement. So keep us posted with your questions and plenty of pics of your progress.
Jared Jones