Buying Lease Land vs Real Property
A book could be written on this subject.
I offer a few guidelines.

Lease land homes are NOT LISTED in the local Realtors multiple listing data base (MLS)
Lease land homes listed through a mobile home broker rarely allow competing brokerages, or Agents to show their "listed" homes.
There is no licensing of individuals/agents selling lease land homes.
The mobile home Broker/Dealer has a license issued from the
Florida Dept. of Highway Safety and Motor Vehicles
Lease land brokerages usually tack on some kind of "administrative fee" from $50. - $300. in addition to the price of the home.
Sales tax must be paid on lease land homes.
The State of Florida charges a one time fee of  (?? $60. PRICE CHANGE 9/1/9) per title to transfer ownership of a mobile home.
The State of Florida charges an annual tax based on length of the mobile home.
Financed homes have additional charges.

Buying directly from an OWNER can reduce the state sales tax by subtracting the $ value of furnishings from the total sales price.
A mobile home BROKER or DEALER CANNOT do this!

A singlewide home on lease land/rental lot starts at $1,000.
A doublewide home (two titles) on lease land/rental lot starts about $5,000. 
the year built beginning about 1970 and would have monthly rent starting around $400. as of 2010 and may not include water/sewer/trash ($32. - $60.a month).  

There are no viewable records of how much a lease land home sold for - no "comps"

Florida Statute  - FS 723 are the laws governing lease land Parks.
 Please see http://www.myflorida.com/

A single wide home with real property starts about $12,000.
A double wide home with real property starts about $20,000.
Title companies or attorneys will give you a written estimate of closing costs.
Closing costs include title search/examination/title insurance/County recording fees/transfer of mobile home title(s)/document preparation/closing fee including the Proprietary Lease for Cooperatives.
A few Cooperatives charge extra $$ for their Association attorney to prepare the Proprietary Lease.  The Association's attorney transfers the share certificate after the closing but the fee is collected at closing by the title company/attorney.
Financed homes have additional charges
The year built would be prior to 1980 and have monthly maintenance fee of around $100.
usually including water & sewer.
Homes that include real property have annual property taxes which will be based on what the new owner pays.
Cooperative share ownership is
Real Property and can be Homesteaded
(RP black background sticker)
and may qualify for a
$25,000. or $50,000. Homestead Exemption.
please see
http://www.taxcollector.com/   http://www.manateepao.com/