Buying a condo based on square feet is like buying a car based on square feet. You can get a poorly built condo with no amenities cheaper than you can get a well built one that is loaded with upgrades and amenities. Also location will affect square footage prices. Checking square feet prices in a particular building is more accurate. I do agree with Mark...find a place that you love and want to live in and start from there. If condos are what you want, there are great deals all over town.
As for the discounts, the list price is going to be very close to the sales price. You will fare better to offer as close as possible to the list price and ask for more upgrades and closing concessions.