I actually sent a follow-up email to Yamas to ask for more prices, and didn't get a reply for a few days.
But today, I actually got a phonecall at work (my number is in my email sig) from 'Tats', confirming the extra parts I wanted, discussing my Lambda's, and him recommending against my trying to replace dust covers due to the high chance of failure.
I think the difference was that I actually sent my original email to the service department, 'Accutech' rather than the generic Yamas email address. They might butcher a pair of phones every now and again, but seem to be genuinely interested in helping people