D40 Lens, 70-300 or 55-200?

I'm taking a new photo course, and if things go well financially I may be able to spare some for a new set of lens, seeing at the AF on my stock 18-55mm died, but manually its still good. Two that I was looking at were:
http://www.amazon.com/Sigma-70-300m...ie=UTF8&s=electronics&qid=1237822202&sr=1-214
http://www.amazon.com/Sigma-55-200m...ie=UTF8&s=electronics&qid=1237822202&sr=1-207

I played with my friends 55-200mm, here are some shots:
http://fledmorphine.deviantart.com/art/a-warm-day-in-hell-116773609
http://fledmorphine.deviantart.com/art/FML-116771486
http://fledmorphine.deviantart.com/art/jerraff-116770928
http://fledmorphine.deviantart.com/art/negative-116770338
http://fledmorphine.deviantart.com/art/days-116768528
http://fledmorphine.deviantart.com/art/counterfeit-116772943

I was always a fan of wide-angles but I really had fun snapping photos with her 55-200mm.

EDIT: Just read the 50-200mm doesn't have a interior AF motor, no wonder the nikon one is more expensive. FML.

ChrisA said:

Buy a used 18-55 they are cheap on the used market.

If you are taking a class wait. Wait until you know something about the assignments you will get. Then buy something suited for that. In general a 200 or 300mm lens of very long and not well suited for general use.

Click to expand...

Alrighty then. Should I buy just the normal Nikon one or is there any benefit to other brands?

http://www.amazon.com/gp/offer-list...3?ie=UTF8&s=electronics&qid=1237943845&sr=8-3
http://www.amazon.com/Sigma-18-50mm...3?ie=UTF8&s=electronics&qid=1237944767&sr=8-3

Is that 18-50 good? Someone pointed that out to me. If anything, I also do shots outside of class.

EDIT: Nevermind, I need to catch things when I first look at them. The ones on top doesnt have AF, so buying it would be irrelevant to the problem I'm trying to solve, but the bottom one does, so I'm going for those, and possibly keep the other for MF if I need it. If I dont ill just sell it.

dlegend said:

You should be able to get a Nikon 18-55 for around $100 used on craigslist, I've seen an 18-55 and a 55-200 together go for less than $200.

That or the new AFS 35 for $200

Click to expand...

The 18-55&55-200mm combo you see in the first link is only $149, but the reason I need an AF one is in case I want to take a quick snap, or something casual.

And yeah, I know there's that, but like would there be an advantage to the sigma? Cause like, I can probably still keep the Nikon for just MF, or should I just buy another Nikon 15-55 and sell the broke one?