To put it another way: The rules say you can use a Staff as a Quarterstaff. It does not say you can use the end of a quarterstaff as a staff implement. If that was true, you could use each end of the quarterstaff as aa Staff, which would then each bet treated as it's own Quarterstaff, which would then each be treated as two Staffs, so hypothetically you would have an infinite number of sub-staffs. That's not exactly logical is it?
Except you're confusing the five gold staff listed on the equipment guide for the entirety of all staffs. Absolute nonsense. That's like saying all 'mace' class weapons must follow the 'mace' entry on the weapon table; that means that clubs and greatclubs, being maces, must therefore do 1d8 damage and be versatile, even tho they have completely different entries than the mace.... yeah.
See... your logic is absolutely irrational. Taking the listing for a singular discrete object and saying it applies to all objects that share a property with it is absolutely nuts.
ONLY THE FOLLOWING THREE THINGS ARE CONSIDERED QUARTERSTAFFS:
The Quarterstaff.
The Arcane Implement 'Staff' that is listed in the list of arcane equipment.
A Magic item that is enhanced as a 'Staff' class magic item.
NOTHING ELSE.
By the same logic as well, if you have a Flaming Quarterstaff +1, you'd not be allowed to use its power to 'flame on' if you were a fighter, because according to the entry on Magic Items: Staffs, the powers of a magic item: staff can only be used if you can use it as an implement. This logic is utter buttkiss, because the entry on Magic Items: Staffs do not apply to the entry on Magic Items: Weapons.
It is logical to assume therefore that just because rules exist to apply to one specific object or group of objects, that that rule does not necessarily apply to all objects that share a single property with that object or group of objects.
This is what is true:
---- No distinction is made between the staff weapon group and the staff implement type. Any and all feats that require you to choose one allow you to choose either. This is -exactly the same- as how there's no distinction between the light blade weapon group and the light blade implement type. I know this part is hard, but if you have a feat that says 'choose an implement type' then 'light blade' is a perfectly legal choice, because it IS an implement type. Staffs follow the -same- rule because there IS no listed exception.
---- 'You can treat the staff as a double weapon. As a double weapon, both ends of the staff deal 1d8 damage. The primary end gains the defensive and stout properties, and the secondary end gains the off-hand property. For more information on double weapons, see adventurer's vault p10'
'Wielding a double weapon is like wielding a weapon in each hand. In the table, the first line of the double weapon’s entry describes the end of the weapon wielded in your main hand. The indented line describes the weapon’s other end, wielded in your off-hand. The two ends of a double weapon can have different proficiency bonuses, damage, properties, and weapon groups. The weight and price entries represent the total for the weapon, rather than only one side.'
'An enchanted double weapon gains all benefits of the enchantment on each end (even if one end would not normally qualify for the enchantment). This does not increase the frequency of use of any power possessed by the item; if you wield a double weapon with a daily power you can still only activate that power once per day.'
This is the sum-total of rules text on the issue.
Firstly, when you use staff fighting with an enchanted quarterstaff, it IS considered two enchanted weapons.
Secondly, absolutely no text exists that claims or otherwise hints that this is splitting the quarterstaff into any object that is described on page 221, or on 240. I do not know who thought it did, but the text clearly indicates you're making this crap up. Therefore, you cannot be using an infinite recursion of quarterstaves, nor does that interpretation make sense under the rules.
Thirdly, enchanted weapons can be used as implements if they qualify.
Fourthly, you have, by the rules, two enchanted weapons. Therefore each enchanted weapon can be used as an implement if they qualify.
Fifthly, each enchanted weapon is a staff.
Sixthly, if you are of a class that can use staffs as an implement, then you can use staffs as an implement. Tautologies are hard!
Seventhly, you have two staffs, one in each hand.
Eighthly, you have an implement in each hand, and DIS is made happy.
Each one of those points above IS the rule as it is written. It works.