The equalizers themselves are under $150. I can't imagine a shop charging more than $500. It should only take them an hour. Very simple item to install.
Ours came with the Cre-3000 and wet bolts. Still the trailer had a bounce to it on less than perfect t roads. I found a nice difference installing the Roadmaster shock kit. I did the install myself but I can't imaging the labor being more than $1000. It only took 4 hours to install. It might be worth asking what they would charge for this while the trailer is in the shop anyway.
https://www.etrailer.com/Trailer-Leaf-Spring-Suspension/Roadmaster/RM-2460.html
2022 Ram 3500 Laramie CTD DRW Crew 4x4 Aisin 4:10 Air ride.
2020 Grand Design Solitude 2930RL 2520 watts solar. 600ah lithium. Magnum 4000 watt inverter.