Hi exfarmer,
Those high feed in tariffs were excellent, a mate of mine is still getting 66 cents but as you say it was a 10 year deal and his is also about to expire back to the 12 cent rate over here. As your system has certainly paid for itself you can upgrade to the bigger system for probably another $10,000, not sure if you have any government incentives like we have over here. It will pay for itself but you will still get a bill for the supply charge, maybe seeing you are in the West you may get more sunny days so this might chew into the supply charge. If I export 20 kwh per day that is my break even point which pays my power and also my supply charge. You can never get close to that with a 2kw system with a feed in tariff of 12 cents because here if you connect to solar your peak step 1 rate increases from .229790 cents to .33044 cents so that is a 33% increase. I can't see how a 2kw system would ever pay for itself under these circumstances.
Go as big as you possibly can with your system because that is the only way you can make this work for you.
