In a rising market a developer marks his price according to the volume and velocity of sales. During this phase there is no secondary market, and therefore normal market forces are absent. The purchases are being made on emotion and expectation. Vast sums of money are spent on marketing and high pressure sales techniques are used to induce a purchase.
If a developer has now reduced the price of the remaining properties in order to sell them, then clearly if you complete you will, if you have agreed to buy at a higher price, crystalise a loss. That loss may or may not be recovered in time. If the other units are not sold and if the developer goes bankrupt completion will place you in a worse position.
You can either allow your option to expire and lose the deposit you have paid, or negotiate. If you really must buy and there is no turning back, suggest to the developer that unless he is willing to sell the unit to you at the price he is now selling all the others, you may not wish to complete. Star negotiating as you never know how strong your position is until you push the other party to the brink.
