Mira Mar Motor Sports is really not that over priced. I shopped them and ended up grabbing a dealer creampuff From Carlsbad and building my own but didnt think they were too out of line with pricing. They tack on maybe 1k or 2k extra for the aftermarket stuff but if you were to pay someone to do the same stuff you are not far from where they are. You can finance the pre modded rigs they sell as well, so there is some value in that. Prices have been creeping up on the GXs, actually all used cars, but that should change in a few months. That said, i put up a post on facebook GXOR offering $200 bucks to someone who points me to a GX that i end up buying. I got a ton of responses but make sure you specify no autotrader ads or the like. Also, turn on alerts to all auto sales sites. The one I bought went up the night i posted on GXOR and i bought it the next morning first thing. Was about to fly and buy to houston but the one i bought was 5 miles away.
non-nav is a big ask. The later ones have an AUX port, 08 and 09 i think, which works well with a little bluetooth AUx adapter.
did you create an account on Lexus Drivers and run vin numbers? huge help and you can see what services and recalls have been done.