1,5M was crazy due to the terrible secondaries. But still, an 18 year old HOF with respectable in all outside skills is very expensive. An 18 year old HOF with Average in all outside skills would still be very expensive i believe. 6 * Average is probably what you should compare him with. 11 pops from draft til now is not perfect, but it´s not bad at all.
If you´re a believer in elastic effect I guess you´d pay extra. Paying millions for a player who´ll probably never be worth more than 2 million no matter what training scheme you have in mind is never a good idea....
You should hope for a foreign team with a training-motivated coach to pick him up, and save your NT-loyal coaches for other players that have more secondaries. Those are the players that would be a dissaster to lose to a possible future inactive team.
Maybe this player will be a asset for your NT in the future, but I have to think that Guards without OD and IS will not be key players on NT-level in 8-9 seasons..