Everyone can look back in hindsight and say "I should have bought in the crash." Then why did so many people jump ship and short sell in the crash? It's because everyone has different motivations, different circumstances in their lives.
There's no really right answer unless you know for sure where the market is heading, and if we could all predict the future, all of us would be in the 1%.
The best answer to the question of when to sell or buy is when you can afford to, and it's the right property.
If you can afford a house at what we're calling the "height of the market," then you should be fine. Even if the market dips, you can afford the payments (Please people, get a 30 year fixed and you're mortgage is like rent control for 30 years). Some people have bought at the height, but got some amazing interest rates, so they ended up just as good as other buyers who got locked into a higher interest rate at a slightly lower price.
If you're selling because you need to, or you want to upgrade, or you want to cash out on equity and get a better investment, go for it. We're at new heights so if you're looking to sell, then duh, this is the best time. If you're not needing to sell, there's no real reason why you should, and it's not like you're needing the cash right now, then hold onto it. You can always rent the place out for killer rents--just as prices are high, rents are even higher than ever before.
