Except as the lawyer on the forum says during 2000/1 I cannot see anything to be gained by buying off-plan. If property prices are going up quickly then so are resales. If you buy a resale instead of waiting 2 years or more you have the use of the property or rental income and the value is still increasing and you are not taking chances with a developer.
A friend came out here to Malaga with the money to buy a modest apartment and was talked into buying off-plan instead. Because of the 2 year wait (which turned out to be 3!) they went over their budget. So, when they could have been enjoying their purchase they had to wait 3 years. End result they have an apartment in a block where nearly every one is on sale and a view of a big pylon from the terrace. With resales what you see is what you get.