It's a Lexus/Toyota, so it should run forever.
Since original owner, would be helpful to post up a pic of the window sticker. Lexus's have a HUGE range in price for the same model, based on how decked out they are.
My wife has a 2014 GX460 (thankfully she still loves it and has no interest in anything newer). Hers is the top of the line model with every option that Lexus offered, and the MSRP was about $70k. "Base" models (parenthesis because no Lexus truly is base or basic) for the same model were about $55k.
Is title "salvage"?