ok, i'll leave the 'experts' to it...
I'll continue decals at $20, you continue at $200, see who sells more 

As a part-time/casual employee for my uncles former printing business, i can assure you i ONLY use pro vinyls & laminates.
Looks like i get my rolls cheaper than you guys.

I only need 560mm rolls for cab-decals, why waste it on (pricey) 1200mm ?

anyhoo....

560mm will be enough for EM and SS machines. Reason i said 1200 wide is it alllows you to print 2 sides on the one width with border and actually costs less this way. What you say is true - more you buy, less it costs

Not sure youll get anything like a DMD from 560mm vinyl though, pretty sure youll need over 620mm for this.

But Hey!! I wish you all the best and look forward to your products and prices