Generally, anything that you must hold in order to activate is treated as a slotted item for cost purposes - it takes up a "hand" slot.
Therefore, there'd be no reason to assign a cost difference between a metamagic rod of quicken and a pair of metamagic gloves of quicken.
However, because this would be a wondrous item rather than a rod, you might run into slot affinity issues. Gloves have affinity for "Quickness." I'd say that the quicken metamagic feat meets that criteria, and therefore there'd be no cost increase.
The next issue to consider is the limitation you are placing upon the item. Specifically, anyone can use a metamagic rod of quicken; only someone who already possesses the Quicken Spell feat could use your gloves. That might warrant a slight reduction in price. I'd recommend no more than 10%, and probably would not apply one at all. The benefit of the gloves is that you can wear them all the time, whereas a rod must be drawn from its holster in order to be used.
Just some thoughts,