| CL 13th is kind of self-defeating, since dispel magic caps at +10 to the check...
No way is this ring, at any CL 5-10, worth nearly as much as those pricing guidelines. As for the "steps," to a move action is not a step. No spell, except maybe one celerity spell, is a move action. Casters don't really care about move actions anyway. I'd dare say casting as a move action would be an even better deal than swift/immediate, as then you could cast 3 spells in a round.
Immediate is a bit better than a swift action, but I don't think that much. I'd say it depends on just how much the effect can interrupt another creature's action. Dispel magic could interrupt it by quite a lot, counterspelling a casting. But at CL 5, it really won't have much chance of doing so, and will eventually be worthless.
The ring of spell battle might be a little over-priced, and if you want to also increase it's cost, whatever. I still don't think this ring should be worth more than 12,000...and i wouldn't even want to pay that much for it. Maybe part of the issue is that it's a dramatic effect, but extremely limited in usage. If you increased to say...3/day, maybe then you could make it 12k or similarly expensive and be more worth it. While still being no more a threat to ruin any one particular combat. | 
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