[quote=nostradamus]No, you should wait until the cost of owning is equal to or less than the cost of renting. So rents have to rise or home prices have to fall.
I bought in 1998.[/quote]
This is a great strategy, and offers good downside protection. The only problem is there have been at most about 4 or 5 years in the past 30 years where you could do this in San Diego.
We are likely entering (or are already in, depending on location) another one of these windows. The problem is that one also has to be ready from a personal standpoint (career, family, financial situation).
I would suggest that one should buy when they can afford to, while avoiding times when the market is extremely overvalued (e.g. 2003-2006 or 07) in relation to rents.
My rule of thumb would be when the cost to own is equal to rent plus a modest mid-sized sedan car payment (e.g. $300-400/mo or so). It is easy to forego a new car as the price to own versus rent.