That is not true. I bought my house 2 years ago brand new, I mean BRAND NEW, never lived in.. for only $180K plus closing cost.
The condo I want to buy is on Lake Emerald. About 4 miles from the beach. I am right under 3 miles from the beach. I can (and often do) ride my bike to the beach. It has a rental base of $875 per month and tenants are already in it.
Actually, sitting directly on A1A, there are condos going for $300 that is really good size. About 1600 sq ft. About 20 yards from the beach. It is the newer models that are high priced. 4 years ago, my priest friend bought a condo at Le Hermitage for $280 on the 22nd floor. The identical unit next to his sold in November for $860. You can find good deals here. If you don't mind an older updated building, you can get condos on the intercoastal for around $140-$190 for one and two bedrooms. If you go slightly west and north up to Palm Aire, you can get 3 bedroom, 3 bath penthouses for about $250.
Buying a house on the water gurantees you ZERO privacy. My BF has a 6M house on the intercoastal and he and all his neighbors have their lives and backyards open to view from any boats going by. No matter how you try to have privacy, you don't Unless you plant wall to wall 40 feet bushes along your waterfront. Because the intercoastal tour ships are over 30 feet high. If you do that, then they can't see in, but you can't see out and lose your view.
Now Miami is ridiculous overprices and under quality, but who wants to live there anyway? Good deals can still be found in Aventura, Hollywood, Lauderdale By The Sea, and Pompano.