Several Web sellers (Buy.com, Amazon, etc.) are listing the Pioneer DVR-R100 drive at around $80 since there is a $30 mail-in rebate specifically for their sites.
Best Buy is not party to this and has responded by putting the same drive on sale this week for $50, in-store, no rebate needed, good until March 18. This is a 16X writer (8X dual-layer), not especially noteworthy except that it is very fast at ripping data.
The DVR-100 is the retail pack (includes several software items) version of the DVR-110D. There is a new version, DVR-111D, which adds 5X writing of DVD-RAM (the others will only read DVD-RAM).
Links:
Videohelp.com DVD writer page
CDRLabs review and tests
cnet review
Newegg has the OEM versions for sale at slightly less - approx $43 with shipping.
