Looking to get a custom bbq island built and hoping to keep costs to a minimum.

Features:
-4 burner grill (propane)
-side burner
-fridge

I want it to be curved, and also have a bar top counter. Pic shown for general idea/shape

Questions:
-when asked about the materials I want to use (structure, sides, countertops, etc) ...what are the ones that are most cost effective? And what ranking?
-what price range seems appropriate ?

Any info and insight for someone who has no familiarity would be much appreciated! Thanks!