Originally Posted by
shelbyfv
If it is a Shimano or SRAM cassette the lower models will shift just as well. The LBS is probably replacing with the same level you had. If you are 5 pounds over "racing weight" the weight of the cassette is immaterial.
+1. This is good advice. You are lucky that your LBS didn't try to "upgrade" (read $$$) your cassette unnecessarily.