Yesterday I had to get a new chain so on recommendation of my LBS, I went with the top of the line SRAM.

The mechanic noted that I had a "wave" pattern of wear on my Shimano cassette and recommended a new SRAM cassette. I might do that Friday but do I really need it? I ride about 50 miles a week (commuting and working out).

Also, my crank's gear teeth has what looks to be a cheap chrome plating flaking off. Should I worry about this? Do I need a new crank?