You pay GST on nearly everything you buy, why does it make you nuts to do so on a new condo?
You could always try to negotiate a lower price on the condo, in order to offset the additional amount you'll have to pay in GST (you will still have to pay the GST, but the overall amount you pay would be lower). You could also avoid the tax entirely by not buying a new condo, there are lots of tax free used condos on the market.
However, if you must have new, then you'll need to stop crying and suck it up. Along with PTT, and annual property taxes, its just one of the costs of owning.