Talk to broker and on the basis of having a decent amount of ncb on your first car, they might indeed give you some level of introductory discount on the second policy, as suggested. That's a standard practice in the industry, but only some brokers/insurers do it (if that makes sense).
As for rough price, 50p?
No but seriously, how long is a piece of string?!
it's all driven by; Dob, postcode, car you're insuring, ncb, previous claims/license history of all drivers, mileage, type of cover required, security, where the car is stored, value and then what the computer says based on that... Not only do we not know all of those things, we don't even know one!
Only way to get a price is to get a quote I'm afraid.
Ps TypeS isn't rare at all these days, every man and his dog have one
And in black, too! 
