What is flat rate for replacing 2 front struts/coil assemblies on 1994 Buick Lesabre?

I would estimate 1.5 hours to do both struts, provided you are installing Quick Strut assemblies. Most outfits will charge $250 to $300 labor, plus parts.

Labor time calls for 2.4 hours flat rate but many shops will have a fixed price for that type of work. Dollar labor charges vary significantly from one area to another so it will pay to call around your area for the best rate. Don't forget to ask about the technician credentials and any warranty that is offered.
Might I also recommend: iATN's Auto Repair Shop Finder