I followed up your PM on here. Good info for all.
Ok, looked at your pics and here's my advice for your budget. If you plan on racing, you need to think that way when planning your mods. First off, you need to upgrade your filter and exhaust, re-jet the carb. That will liven up your bike a lot if done right. You can choose to go in more with the engine but its up to you. (mid upgrade would be bore, cam and springs) Also consider an oil cooler. Racing full speed for 1.5 hrs really heats up the engine, the cooler it runs, the smoother and longer lasting it would be. If you go filter, jet and exhaust, no cooler should be fine. Mess aorund with gearing a little as well is you so choose.XC is all about the bottom end get up and go when you get in those tight sections.
So, very basic; exhaust, jet, sprockets and pro-flow kit. Around $400 bucks, maybe $300ish if you go with a used exhaust (don't buy DG or Cobra, they are just as good as stock HP wise)
Next would be your front end, since yours is bad, you can rebuild it all and look for some off set rims or flip yours. Or opt for some a-arms. Its up to you, I say if you want width do it the right the first time the right way and go with the arms. It will save you money and hassle in the long run. Shocks are a must! especially on our style bikes. Going on the cheap, look for some used WORKS shocks off of a banshee. At least the fonts. Get a used stock banshee rear and mod your air box for the fit. You can get a front set of nice works with rezzies for $300 and you might have to re-valve them for your weight. (another $100 or so)
so far your at $600 or $800 and you have a little more speed and a waaaay better ride. Another $400 for the a-arms and $200 for the rear axle to match the width and your at $1200-$1400. After that, you need tires and a gripper seat. Keep your bike on the ground and going and you on the seat controlling. The cover you can get for $40 - $60 an tires really vary. (I ride BKT AT-111HD's maxxis razr II clones, kick ass tire, tons of bite and really affordable.) That might be all your budget for now depending on if you find deals and what you buy.
You'll have Shocks (better ride makes for a comfortable and un-exhausting rider = you riding faster), Width (makes for a wider and more stable stance, you can ride faster with more controll not fearing a tip over and it deff. helps on the off camber stuff) Grip (puts your power and maneuvering on the ground and keeps you on the seat with the cover) and a Better Breathing Engine (breathing better, gains a few more HP's).
With the left over money: an engine kill tether/kill switch. Hand guards, belly skid, steering damper, and an advanced voltage battery are all really nice racer types things to have. Don't forget you need gear to! Helmet, goggles (tear-offs or pull wipe) boots and gloves are a must. Riding pants and jerseys are great if you can afford to get a decent set.
Its a learn as you go process. Learn what you need to make you comfortable on your bike and you can be as fast as anyone. Start with the basic necessity's first and then you can mod with accessories as you go along. Performance first, looks later. (hahahah, I should be one to talk, I jumped all over the place, witch if you find deals on stuff your gunna get eventually, by all means hop on them!)
Have fun out there and learn form experience. Race to your level and push yourself to get better. Most of all have fun!