A heads up. There's real turquoise and then there's a fake "turquoise" out there which is dyed magnasite or howlite. There is also "Enhanced" or "Treated" turquoise which is low-grade turquoise dyed to look better. The price/value of turquoise is dependent upon the type (Kingman, Sleeping Beauty, Royston, etc.) and whether you're looking for shaped beads or chips/nuggets. Shaped beads of real turquoise are expensive. You're looking at around $20.00 to $60.00 for a 12" strand of beads about 5mm in diameter. Those would be rondells, round beads, flat discs, and barrels. Heishi can run you about $26.00 and up. Chips and small nuggets drilled as beads will only cost around $5.00 to $16.00 per 12" strand. These are the new, off-the-shelf prices. Of course, trade value depends on mutual agreement. New prices can't be applied to used strands unless you're talking about something like Morenci, Bisbee, or some other rare turquoise.
My mission here is just to give you a heads up that there's magnasite out there which looks a LOT like real turquoise and only the trained eye can spot it. If you need real turquoise, well, it pays to ask questions about the source of the turquoise. You can find turquoise strands at antique stores and so on but, again, it could be magnasite. We call magnasite "tourist turquoise" here. I sell bulk silver and turquoise for a living and to be clear, I'm not selling it here. I don't have any of my own that I can trade right now. I only wish to offer advice on acquiring it for yourself. I can tell you what to look for to ascertain if you're looking at real turquoise or magnasite.