What should I offer for an oceanfront apt. in Miami Beachthese days?

[DoubleDealDecker]

Don't offer nothing for it. We are at the end of a very serious housing bubble and it will probably blow up big time.
If you must, listen to what apex said about 50%. The best thing you can do is wait at least 6-12 months. I promise, you
won't get hurt. Forget about 20%, it is not enough to cover your downside risk.