Start small with conservation.
Maybe plan on converting lights over to Solar, and then move some additional things over.
Then target some of your power HOGS like converting to Solar Hot Water.
As far as cost..
Consider the construction of the Bonneville Dam. It took approximately 3,000 employees, 5 years to construct (working around the clock shifts). I presume the expected payoff was 30+ years. Thus, you might not expect immediate return on your solar system.
But, then again, I doubt that Electricity prices will stay fixed for the next 30 years either.
As far as my "crystal ball". It is a bit cloudy, but I would anticipate prices to start dropping significantly in the next few years. But, perhaps that will be comparing apples and oranges. The durable 25 - 50 year silicone based cells will likely stay pretty flat in the future (with inflation catching up creating the illusion of lower prices).
However, at some point, there will be rolled thin film solar panels that can be applied to the purchaser's substrate (metal roof, vinyl, etc). The price on this will probably drop to less than $1 / watt in the next decade. However, my guess that it will be designed to have a 10-15 year lifespan, far less than the silicone based cells.
Look for higher efficiency cells in the near future. Some manufactures (Boeing/Spectrolab/Emcore) claim 30+% efficiency. However, the efficiency is only a measurement of the size of your panels. A 30% efficient cell should take half the space of a 15% cell for the same amount of power.
Perhaps the biggest effects on the prices of the cells and panels will be a basic supply and demand curve (except, not quite "classic"). Right now, the demand is very low, but it overwhelms the current manufacturing capabilities. If, however, the demand would go through the roof... then there would be a resulting higher production, and the cost would drop (and demand would go up further). Just think what would happen if Home Depot would start selling more solar panels than 2x4's.
Anyway, who knows. You could buy a $5K array today then find the price is half that tomorrow. Or, you could buy a $5K array today, and find that it jumped to $10K tomorrow.