I have a nice Arcteryx Bora 80 backpack for sale. 

Its a good internal frame backpack capable of carrying loads for long multi-day/week trips.

Back view of back

Shoulder straps and waist area

Side view

This Backcountry.com's information on this pack: http://www.backcountry.com/arcteryx-bora-80-backpack-4700-cu-in 

This the pack when full of gear. (original image from website)

This is the Trailspace gear review of the pack:  

Its the tall sized pack. 5400 cu in 82L extends to 5614 cu in 92L

Weight empty 3.2 kg 113 oz

Looking at $60 plus shipping

I bought it last year from another TS member but have decided its too big a pack for my needs. I paid $100 for it.