What competition are you trying to go to?
If you're just getting started with competitions and going to local tournaments, you don't need very high-end expensive gear. You need a hogu, helmet, arm pads, shin pads, instep (foot) protectors, gloves, cup and mouth guard.
I've never bought from this company, I just found them looking on google just now, but something like this should be more than enough:
Complete Tae Kwon Do Sparring Gear Set for $88.95 with $4.95 shipping!
If you have experience with tournaments and are looking to go to high-level WTF ones like the US nationals (I think you said you were American before?), you'll need WTF-approved gear. That same company also has another set on their website that's a WTF-approved Adidas set:
Complete Tae Kwon Do Sparring Gear Set for $228.95 with $4.95 shipping!
In either case, you need either a white helmet, or BOTH a red and a blue one.
Edit: I just posted the URL for those links. I guess the site automatically generated those page titles, haha, which aren't even the prices listed on the page.