The price you can get for an aircraft always depends on many things. The most important ones are condition, age, and time until next C/D check. Price can fluctuate anywhere between 80&-200% of aircraft value, depending on current used market status. For example, right now there's a huge demand for most of the airplanes, but little demand, and this with low fuel price has resulted in companies having lots of extra cash available to use on planes, thus people can ask more for their planes.
But, in a few years, if the prices go up and companies start to fall and the market gets saturated with planes, it can be very difficult to sell your plane at a decent price.