I literally came back from shops right now asking the same thing. One shop quoted me 2 hours at $115 per hour and allowed me to bring in my own shocks.
Les Schwab quoted me $79 per shock install, but I have to buy them there. The rep told me that the system was showing that he had to call and check for delivery date because they weren’t showing up available. He said the 5100s run about $400 a pair.
Tire Factory told me it would be about 1.3 hours at $120 per hour; i’d have to buy the shocks there too. He told me the 5100s were on national backorder.
Where did you get yours and how much did they cost?