Finding A Weapons Master

I was talking with my co-DM about weapon trainers, wanting my character Nick to get some training, but there isn't anything that suggested how likely the PCs were to have on available locally. So, I came up with a chart. I'd had a half formed idea already, since several of my players have taken advantage of the weapon training rules, so this really just codified the idea. 

Keep in mind, the arrangement of weapons into the different categories is based on my campaign

Chance of finding a weapons trainer in a large town. Chances reduced 50% for small towns, and 75% for villages. Cities add 10% base chance shown below.

Teacher Level	Common	Uncommon	Rare	Very Rare
Skilled	75%	65%	55%	35%
Expert	55%	45%	30%	20%
Master	30%	20%	10%	5%
Grand Master	10%	5%	3%	1%
	Common Weapons	Uncommon Weapons	Rare Weapons	V. Rare Weapons
	Axe, Hand	Crossbow, Heavy	Blackjack	Blowgun
	Axe, Battle	Hammer, Throwing	Lance	Bola
	Bow, Short	Hammer, War	Trident	Shield Weapons
	Bow, Long	Staff	Cestus
	Crossbow, Light	Javelin	Net
	Club	Polearms
	Mace	Sword, Bastard
	Dagger	Sword, 2 Handed
	Spear
	Sword, Short
	Sword, Normal
	Sling
	Thrown Objects (rocks, oil, holy water, etc)