Think of all the possibilities before you decide to buy.
Say housing busts after you buy and they haven’t finished the conversion on the entire complex yet, what will you be left with? You’ll have an apartment that you “own” and you’ll be paying a bunch more than rent to your new landlord, the bank. It might be hard to sell a house if housing busts, but nobody is going to touch a conversion in a down market. On top of that, how will you feel if they have to revert the remaining units back to apartments, or roll back the prices for the rest of the units? You think you’ll sue? What if the original company goes bust with the housing market?