We've probably all said (or at least thought) "If I knew then, what I know now, I would have done things differently." We should have stayed in school longer. We should have listened to our parents. We should have bought Apple stock in 2002 for $8.50 or gold in 2000 for $300.

Years from now, if we look back at 2012, it may be clear that this was the best buyer's market ever. The prices are down nationwide 35-40 percent from four years ago, mortgage rates have never been this low and rents are rising. Few homes have been built in recent years to keep up with a growing population. There may never be a better time to buy homes than now.

The housing affordability index, which is considered to be good at 100, has increased to more than 200 for several months. Shrinking inventories and rising prices in some markets are causing the index to fall for the first time in years.

This "buying" opportunity applies equally to acquiring a home to live in or to rent as income property, or maybe that vacation home you've been dreaming about. It is estimated that about one-third of the homes purchased last year were bought by investors. It is reasonable because the positive cash flows far exceed most other investment alternatives.

The question we're all faced with this year is whether we'll be saying we seized or missed an opportunity of a lifetime.