There's a site that has the ACR Aquafix 406 with internal GPS for $477.74. They list one price, but sent me a link with a lower price when I wrote to them. By comparison, REI has the ACR Terrafix 406 with internal GPS for about $595.38 (LA County sales tax included) out the door if you do store pick up; it's more if you choose direct shipping to your home or office. If my math is right, that's a minimum savings of $117.91. The Aquafix is the same as the Terrafix except that the Aquafix is blue and the Terrafix is green.
I'm not sure if I should post the link, although it's probably OK to do so, but just in case, I won't. However, if you were to PM me, and ask me what the best deal I've seen on the internet for an ACR PLB is ...
HJ
P.S. I ordered the unit at about 1:45 PM today. I requested standard UPS Ground shipping. I got an email from UPS at about 2:45 PM today, telling me that the item was in their system and that the delivery date would be this Friday. Not too bad of a turn around.