-- Last Updated: Oct-13-12 4:28 PM EST --
This time of year, look for their sales events. You should be able to find, for about $1,200 something like Tempest 165, with luck. Sounds like you want to progress in kayaking and this would be a great kayak for this purpose. The Alchemy will also fit the bill and is more maneuverable but will be slower.
EDIT: just read your under 15 feet requirement, so the Tempests do not fit as they are too long... Pitty -;)
I'd say, pay-up the difference, since you have already committed to REI. If you wait till your annual divident comes (you did sign to be a member when you first bougt, right?) that will pretty much cover the difference.
Alternatively, if that's an option you have and want to pursue, sell your REI credit to someone else at 10% off and buy elsewhere or used at 30-60% off and pocket the difference -;)