So on this server you make a business/enterprise and register "taxation industires" which are gonna be the categories of things you will be selling.
^here you can see the current industries and what specifies each one. So for example if you want a restaurant you choose the "food & beverage" industry.
Price varies from category to category.
For more info just read this https://docs.google.com/document/d/1NZ3gX0DmyHdHvCNHGN_zV53Ar28Qr6Aw41kBeM7ebgk/edit?tab=t.0
Normally now adays they get to do an auction for properties that are up for sale, and they usually range in the mils
For more info i would recommend just going in the NY gov discord and asking in the questions channel, or you could make a ticket with either the DOP (property ppl, or the DOC (business ppl)