With the high capital costs, and unfortunately the difficulty in clients differentiating from one Seneca to another it would be difficult to get much more for the aircraft than a Seneca II, which has the advantage of being under 2000kg MTOW.
You can pick up a decent PA34-200T for under 100K GBP, so the lease in rate would be approx 100 GBP dry maintained insured per engine hour. Not much good to you for the money you just spent on a Seneca V