A good shop will let you try a saddle for a week. A really good shop will let you try a saddle for a month. A great shop will let you try a saddle for 6 months.
Why not try a number of saddles, besides Selle Italia, and see if they work for you?
BTW - I didn't like the Selle Italia either, it was too flat for me. You find your cheap saddle comfortable ... what shape is it? What kind of curves does it have? Is it flat or does it curve up a bit in the back? Whatever the shape of that saddle is, try to find ones like it to try.