A tent, pack, and a sleeping bag for under $500? Easy! Check out Campmor.com. I've gotten a ton of deals there over the years.
Here's a 15 degree Eureka bag for $40. Get a compression sack or compression caps, and you can scruntch it down to a more packable size:
http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=39278143&memberId=12500226
The Lightpath tent you mentioned looks to be a nice lightweight choice. I'd go for the 2-person model at least so you could get your gear inside for the night.
http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=39290692&memberId=12500226
The Sierra Designs Clip Flashlight is a pr oven design and it packs small:
http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=39276148&memberId=12500226
As far as a pack goes, make sure you research sizing at whatever pack manufacturer's site to make sure you get something that will fir you. That said, I just had my hands on this pack last weekend, and I was blown away at how solid it was:
http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=30621942&memberId=12500226
I want it, but I would be stretching its outer sizing limits, so the 45+10 would be the better choice for me:
http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=30621940&memberId=12500226
So, if this was me going, I'd have spent $145 on the pack, $130 on a tent, and $40 for the sleeping bag. Add $35 for a Z-Rest pad, and I'm left with $150 for gas money, clothing, or whatever.
*Disclaimer* I understand you have a choice as to where you procure your gear. By siting Campmor as an example, I am not necessarily suggesting you buy all your gear there. There are many online and local merchants that are worthy of your hard-earned dollar. REI is a great source for gear and knowledgeable staff (at least around here), but you'll pay more for top-notch gear. Sierra Trading Post is another online 'bargain barn' where I have found screamin' deals. To many others to list.
Good luck, and have fun at school!