2 stage will never have an economic payback unless your electric price exceeds 20 cents per KWH. 2 stage purchase is all about comfort. In my own house I went with a slightly undersized unit, 2 ton instead of the 3 ton it replaced. It basically runs on "stage 1" of a "3 ton 2 stage". It can't keep below 75f when temps exceed 100f, but I'm OK with that in order to have better comfort the other 95% of the summer. I'm not paying double for a 3 ton 2 stage in order to maintain setpoint for those 5% of times when it gets really hot outside.
Going with a heat pump (aka dual fuel) may make sense in your area. Use heat pump down to about 40f, then switch to gas. Excellent comfort since the air isn't that hot from the registers during moderate conditions, warms up when the gas is turned on in colder weather. A 14-15SEER single stage heat pump is what I'd install if I was in your position.