Is it possible to get a ball park price for the following size light commercial AC and HP systems - 7.5, 9.5, 12 and 19.5 tons (or around those size ranges) that meet ENERGY STAR.

Probably not, contact 3 companies and get bids. Prices fluctuate all over the country, based on brand, demand, access etc.

They average about $1,250-$1,500 per ton in Florida depending on the size of the duct work. Larger returns and more returns which will increase efficiency will add to the price, but the more returns you have and the bigger the filter area is (2 times footprint of inside unit is minimum, but most companies quote you on 1x filter grill size.)the better the unit will cool and filter air. Look more at what you are getting than the price because you will get what you pay for and saving a few dollars by having cheap duct work will cost you much, much more in energy. Also, make sure unit is where it can be washed out without causing water damage. You want a floor drain under unit because coils need to be washed out once a year to remove dirt and mold. Further, you should have large HEPA filters installed twice the area of the footprint of inside unit or more 3x is even better. Returns should be at each end of house and in some rooms to get best air exchange. DrTom4444