So they are done... about 3 clear coats on them.
Total cost: Matt grill + $22 (primer+paint+clear)
Total time: A day or two depends, it took me 2 days as I choose to do long weekend diy for me.
Worth time and cost?: since no one buys my matt grill, I got myself a new grill with $22 and some time, it was joy and fun time for me
although i screwed up in the end with the clear coating