I think an estimate of $150k for LQ F is a little unrealistic. If the base LQ is priced somewhere around $85k (in between the other flagships, LS, LX and LC), I cannot fathom why an F model would cost nearly double. IMO, base of $85k is even a little high for a car like this... the sweet spot would be something around $75k base because it creates a logical "step up" from upper end RX and GX, can catch fleeing GS owners and opens up a whole new demographic for Lexus: Range Rover Sport, Cayenne, X5/X6, Mercedes GLE43/GLE43 Coupe, Maserati Levante and others. $85k is a lot of cash and $10k+ more than the base for those competitors. This car still needs to have a volume business case behind it, plus Lexus' recent forays into the realm of $75k+ have not been particularly fruitful.
I don't see why the F model should start at more than $115-120k. After all, this is Lexus and they are a practical company.
Dropping the GS, replacing the SC with the RC, and the GX going on ten years unchanged impacts the middle tier of Lexus' lineup... and you start to lose the ability to graduate consumers from that tier upwards. A lot of them will have already left, meaning Lexus needs to attract a net-new customer at this price point. There is a huge gap between $40k ES and $75k LS, and similarly, there would be a huge gap between $44k RX and $85k LQ.