I think it's a pretty close trade, actually. You're downgrading from Longoria to Beltre, which is definitely a hit. You're upgrading from Price to Verlander, which is a nice boost but not worth going from Longoria to Beltre. The key is giving up Martin and getting Jurickson Profar. Profar is an elite, top 5 prospect. He plays great defense at SS, put up insane numbers as an 18 year old in full season ball, and when he comes up he'll play in Arlington.
I still think I would pass, though. I'm not sure I'd want to accept such a sell high on Verlander - in a season or two Verlander and Price may be seen as more evenly matched, or perhaps even Price having an edge. Longoria is a lot younger than Beltre and like someone said above, he really is a special talent. It would be great to get Profar, but the price is just a tad too high.