Interesting concept, but I'm worried about the execution. In particular, Refined Weapons provide too much bang for the buck - you get a +2 attack for an average -1 to damage. Twink mastery would be to take a Refined Heavy Flail (+2 to attack, 1d8 damage), then Power Attack, making up the lost damage dice and more for no real loss of accuracy.
I'd rather see this as a couple of new special material types rather than different weapon makes. 'Elysium bronze', say, might be a special, lightweight metal that provides the same modifiers as your 'refined weapon' type - but costs, oh, 50 gp/pound. Better suited for Planescape and easier for a DM to control.
then the cost ought to be raised. a new special material defeats the purpose of this if you wanted a refined adamantine longsword, say.