Honestly making them is not that difficult.
I made the first set on my own, and after doing so I am going to change a couple things, really the rear vents as I want them to have a cleaner look than what I did last time.
Long story short though, honestly they are not difficult at all to make, and because of that, I would honestly encourage you to consider making them yourself if you don't want to pay someone else's premium. The side vents are the hardest to make, just because of bondo...but since I know now what I didn't then, I will not make the same mistake twice.
If you want details, I will PM you, just let me know what you want to know exactly. I plan on tackling mine this summer when I have some extra time at home...but until then I am just driving around grill-less.

I should point out...that honestly you will be out about a total of $100 in parts (i.e. mesh, bondo, buildable primer, and sand paper.)