KW V3'S to do not cost 2800 a set. its more like 2100-2300 either way what they did is wrong with offering free install and then changing the deal at the end when the buyer committed to purchasing the suspension.
To be honest with you in all of my years modifying cars most retail business's and shops really dont know shit about their products, or customer service. The ones that do know whats up are the ones that you never hear anything bad about anyway.
To the OP the price does seem OK but at the same time they shouldnt have quoted you mutiple times one thing and then try to switch it up on you.
Tisk Tisk LTBMW