SSD's are already going down in price.
Now, if what you expect is a dramatic price cut of around 40%, it will take a at least a year, so I think Q4 2012 for it to happen..
The question is which type of SSD will see such change?.. The SataII class and, of course, the smaller drives.
The SataIII big drives will remain expensive because more capacity will be squeezed in and there's huge demand for that. Some SataIII's with small capacity will be cheaper by at least 30% by then.
Now, the reason why people see this technology as expensive is because we have the tendency to compare the "uncomparable". Please do not put together HDD and SDD with economics in the same equation. These are very different things and you could only compare their performance but don't mix the price in there because the HDD's price is victim of SSD's technology and advantage at present. Picture for a moment a world without SSD.. that it had never existed and not foreseeable ever.. How much do you think a HDD would cost?... yes, is that simple.
In any case, cheaper is kind of tricky: You will be paying the same USD$300 for a top line SDD now, next year and at least for 2 years. It will just be bigger and perhaps 20% faster. That, unless another controller manufacturer jumps in fast enough to disturb the balance.. Then, there will be a more dramatic change. There are many controller manufacturers baking cool stuff at this moment but their muffins will see the streets Q3 2012. The market needs time to adjust, so it's effect will hit you in Q2, 2013.
In 2014, you'll be laughing if you remember this post or find it accidentally. Storage performance/price worries will be a thing of the past, just like RAM is today.