I have a Dana Designs Bighorn and Bomb. Great packs, might be just a little small for a week, but I use mine for daypacks just in case I get lucky enough to knock something down. Paid less than $30 each in great shape.
Same on some old Mountainsmith Frostfire size packs. But my current favorite is a Gregory Forester that I found at a thrift store for $25. Depending on where you live you can find a lot of great packs for far less than $300 on Craigslist.
Lot of great packs sitting in houses that never get used. Makes for some great bargains.