$99 is MSRP and widely available.
Thanks for the post since you mention the rebate, the $50 rebate is good on a number of HD Radios:
Accurian TTR
Alpine DVA-9965, TUA-T500HD,
TUA-T550HD
Audio Design Associates HDM-1
Axxess (Metra) AHDT-01
BOSS 750HD
Boston Acoustics, Inc. (D&M)
Receptor HD
Cambridge Soundworks 820HD
Coby HDR-650, HDR-700
DaySequerra M4.0X, M4.2R, M4C
Denon AVP-A1HDCI, AVR-4308CI,
AVR-5308CI, DRA-697CIHD, S-52
Dice HD DICETM, iTR-100
Directed DHHD-1000, DMHD-1000
Dual XHD6420, XHD6425, XHD7714,
XHD7720
Eclipse HDR105
iLuv i168, i169
Insignia NS-C5112, NS-HD2114
Integra C-HDSAT, DTC 9.8, DTR 8.8
JBL (Harman) On Time 400IHD
Jensen (Spectra) Jims-525, JiMS-525i
Jensen Mobile AMM12HDN, HD5112,
HD5212, VM8013HD, VM8023HD,
VM9022HD, VM9022HDN, VM9312HD,
VM9512HD
JVC KD-HDR1, KD-HDR30, KD-HDW10,
KT-HD300, KT-HDP1
JVC Arsenal KD-AHD39
Kenwood KTC-HR200
LG PC12
Marantz AV8003, SR8002
Niles Audio TM-HD/R
Onkyo PR-SC885, T-4555, TX-NR905
Peripheral (AAMP) HDRT
Pioneer GEX-P10HD
Polk Audio I-Sonic ES, I-Sonic ES2
Polk Designs HDX3
Radiosophy HD100
Rotel RT-1084
Sangean HDR-1, HDT-1, HDT-1X
Sony XT-100HD, XDR-F1HD,
XDR-S10HDIP, XDR-S3HD
Visteon HD Jump, HD Zoom, HD Pulse
VR3 VRHDUA100
Yamaha RX-V863, RX-Z11