No one really is going to have a definitive answer for that. At best, it'll be a guess.
And two other quick thoughts: If you're considering buying, buy the house the works for you at a good price. Let's say, for instance, that there's a house in Gilroy listed for $300,000. The comps say it's worth $300,000. There's a house in Hollister listed for $290,000. The comps say it's worth $350,000. The one in Gilroy is a fair value, but the one in Hollister is a real bargain. It's likely that in 3 years the one in Hollister (fair market value) will be worth more than the one in Gilroy.
Second quick thought: In today's market, don't even consider buying if you think you're going to be selling in 3 years. It might work out OK. But even in a reasonably good market, 3 years is a very short time frame in which to buy and then sell. In today's market, it could be disastrous.
Hope that helps.