I' had them for many many years (and didn't have any problems with them - think I finally thew them out when I moved apartments earlier this year). Anyhow, if the R10 was built the e888's I'd be rather disappointed :p. Vastly different in manufacturing costs I'm sure.
The R10 was built much better, IMO, only L3000 has better build quality among the dynamics headphones that I own/owned. Speaking of the foam rings on the R10s, one can always purchase a urethane foam, cut up and it works just fine. Did that myself for one of my R10 as the Sony parts are no longer available. BTW, you just thrown out a $100 bill. Many are searching for the E888 in good condition. :D