Take a look at the sponsors' websites. They list all kinds of gear and you can compare prices and features.

Trying to outfit yourself for under $300 is tough, but not impossible. Used gear is the way to go, BUT, you need to know what you are looking at and that will take some research. Look at the websites for the better brands. Look at REI, they sell a lot of different brands and have sales regularly. Plus, they will take things back if they don't fit or you don't like them-basically they take back almost anything for almost any reason.

Cheap gear tends to be heavy. That is the tradeoff. With sleeping bags the saying is "cheap, light, warm...pick two." A bag that is all 3 hasn't been invented. Anyone who claims there is just isn't being honest about it.

Buying a second-hand tent is a good way to save money, but you need to know what you are looking at, just like with other gear.

A cheap pack is probably the best place to save. Decent packs can be had for around $100. Won't be the lightest, but will be adequate.

For my money, I'd focus on getting a decent bag, then pack, then tent in that order. If you hike with friends, one of them may already have a tent, but you need your own bag and pack for sure.

btw, a 15F bag for $80? I don't believe it for a minute.