Full break-down of the price:
A dwarven waraxe costs 30 gp
Since we are starting with a dwarven waraxe, we need to start with its price. It is 30 gp.
Only masterwork weapons can be made magical
Non-masterwork weapons cannot be magic. Masterwork adds a +1 enhancement bonus to attack (only), and costs 300 gp.
So we add the 300 gp to the cost of a dwarven waraxe to get a masterwork dwarven waraxe costing 330 gp.
Attacks made with this dwarven waraxe are made with a +1 bonus over regular dwarven waraxes.
All magic weapons require that you have a +1 enhancement bonus first
The discipline property is no different in this regard. This enhancement bonus provides a +1 to attack and a +1 to damage.
The cost of magic enhancement bonuses is x2 × 2,000 gp, where x is the enhancement bonus. So a +1 costs 12 × 2,000 gp = 2,000 gp. This cost is added onto the cost of the masterwork dwarven waraxe, so the +1 dwarven waraxe costs 2,330 gp.
Since it is an enhancement bonus, the attack bonus does not stack with the one from being masterwork, so attack rolls with the +1 dwarven waraxe are the same as the masterwork dwarven waraxe (i.e. +1 over regular dwarven waraxes). However, the +1 dwarven waraxe also adds its enhancement bonus to damage rolls, so the +1 dwarven waraxe does 1 damage more than the masterwork dwarven waraxe.
Discipline “costs” as if it was a +1 enhancement bonus.
Since discipline is priced as if it were a +1 enhancement bonus, and our +1 dwarven waraxe already has a +1 enhancement bonus, we add these together to get an effective bonus of +2. The cost of a +2 enhancement bonus is 22 × 2,000 gp = 8,000 gp, but this is the cost of the +2 bonus in total, not the cost of upgrading a +1 to a +2.
So our +1 discipline dwarven waraxe costs the same as a +2 dwarven waraxe: 8,330 gp. This is 6,000 gp more than the +1 dwarven waraxe.
No matter what, this weapon is always going to count as at least a +1 dwarven waraxe, so you still get the +1 bonus to attack and damage. If you do not know any maneuvers from the chosen discipline, that is all it does.
If you do know maneuvers from the discipline, though, you get +1 to attack (only) from the discipline property; this is an untyped bonus and so stacks with the weapon’s enhancement bonus. So if you know at least one Stone Dragon (for example) maneuver, your attacks with a +1 stone dragon dwarven waraxe are made with an additional +1 bonus over the +1 dwarven waraxe (and +2 over regular dwarven waraxes). The discipline property does not provide bonuses to damage, however, so your +1 discipline dwarven waraxe deals the same damage as a +1 dwarven waraxe, even though it costs as much as a +2 dwarven waraxe.
Finally, though, if you are using one of the maneuvers when you attack (that is, the attack is part of a strike, is improved by a boost, or you are in a stance), then the bonus increases to +3 instead of +1. So if you are initiating mountain hammer, a Stone Dragon strike, your attack roll with a +1 stone dragon dwarven waraxe has a +3 bonus above the +1 dwarven waraxe (and +4 over regular dwarven waraxes).
These are bonuses to rolls, not additional rolls
The +1 discipline dwarven waraxe gives a +1 bonus to attack rolls when you are using the appropriate sort of maneuver. This is just a bonus, like the one your Strength adds to your attack roll.
These bonuses do not confer additional attacks. See the speed property for an example of a special weapon property that does add additional attacks.
Result: +1 discipline dwarven waraxe for 8,330 gp
No knowledge of discipline’s manuevers: +1 to attack rolls, +1 to damage rolls
Knowledge of at least one maneuver from discipline: +2 to attack rolls, +1 to damage rolls
Actively using at least one maneuver from discipline: +4 to attack rolls, +1 to damage rolls