2005 LX470 showing AHC issues on post-purchase inspection. Very expensive fix. Am I getting shafted?

Bought an 05 LX470 on the cheap from a family friend. Took it to a lexus tech shop and got quoted 6k for failed accumulators... is this a normal quote for this? The vehicle is bouncy but overall still pretty comfortable to drive, feels much better than my 08 ranger. I assumed AHC maintenance would be expensive but this is quite literally double the price of what I paid for the vehicle. Should I just get an AHC delete? I'm located in the southeast US.