Kev,
i .... most buyers want to see what there are buying hence before occupancy is a floorplan sale or some pics taken during your pdi, also most will want great discounts to market value because they will use what I said against you with excuses, good for seller is you dont have to come up with the occupancy deposit, usually a further 5 to 10% and pay the occupancy fees
ii.... better time ... buyers get to see unit, but still will want a discount becuase of the closing costs and you the seller may have to pay an assignment fee $3,000 to $5000 to buiider, most of my deals at Nep had $0 fee, buyers position is still wants below market value, assignments usually are below market, for reasons of deposits, profit and closing cost issues
iii.... you have to pay closing costs and a negative maybe an empty unit for the investor, so paying all occup fees from occ period to closing usually 6 to 9 months
The other issue is if you think the market will tank by the time you close the unit, then you may want to assign to secure the gains, there are other smaller details, but I dont want to bore you and write a book