Price on a revalve/respring on yfz450 shocks would be as follows:
This is for the pair not just one single shock.
Labor: $70
Oil: $20
Revalve: $175 (includes new high flow piston valves)
Respring: $209.99
Seals, o-rings, etc. are extra. I will make a recommended list of parts to put back in and call you for confirmation before installing.
Total: $474.99