HPA Tanks

[Seajay]

Got a bunch of tanks out of hydro. Trying to figure out if the cost is worth re-hydroing them, I don't have a cheap way to do it yet.
I can't use all of them, so is it worth getting a hydro to sell.
What would be a fair ask to sell without a new hydro?

Ninja Grey 77 -2014 (no reg)
Ninja Grey 68 - 2015 (standard reg)
Ninja SL 77 - 2016 (standard reg)
Ninja SL 77 - 2017 (v2 pro reg)

[Jonnydread]

Out of hydro with some re-hydroable life left $60-$80 feels fair to me. I tend to buy tanks that are just out of hydro and then get them tested myself, and I have paid anywhere from $50 to $80 depending on the tank, potential life left and regulator.