...if you're doing your headliner then it's free! Otherwise a yard of material costs about $9 plus glue.
I attempted to fix a couple of cracks on my black 740 dash, but wasn't satisfied. I was about to purchase either a molded plastic or carpet cover when it hit me to make my own.
My cracks were mainly near the windshield, so I only needed a partial cover. Having my windshield removed I did the following:
1) Made a pattern out of cardboard2) Laid the pattern over left-over headliner material and trim to fit
3) Applied the 3M light-trim adhesive as per headliner instructions to the cardboard and fabric4) Install headliner fabric on cardboard
5) Clean dash with acetone6) Apply adhesive to dash and new cap
7) Install new dash cap and set with board on top weighted to secure front edge to hide glue.Looks pretty good!