Originally Posted by
Iride01
Why ignore differences in appearance?
Exactly!
CS-HG31 - Black, $17:
Shimano Altus CS-HG31 Cassette (Black) (8 Speed) (Shimano/SRAM) (11-30T) - Performance Bicycle (performancebike.com)
CS-HG41 - Matte grey, $23:
Shimano CS-HG41 Cassette (Silver) (8 Speed) (Shimano/SRAM) (11-30T) - Performance Bicycle (performancebike.com)
CS-HG51 - Silver, $22:
Shimano Alivio CS-HG51 Cassette (Silver) (8 Speed) (Shimano/SRAM) (11-28T) - Performance Bicycle (performancebike.com)
For a $6 difference I would not worry about anything else other than gearing and color. I doubt anyone who rides an 8 speed cassette is a weight weenie, at least not with respect to the bike that cassette is on.