Yeah, a music video (well rehearsed) should easily fit into a 5:1 if not even a 3:1 film to actual time ratio.
100ft is about 2.5 minutes at 24 fps
400FT loads from Kodak are technically $150. But, if you register with them as a business, buy direct and use a credit card you can get discounts to get down to about $125/roll.
Assume a 5 minute music video you should be able to get away with 2 400Ft loads, 3 easily. If you are using more than that, then you are under planning/rehearsing.
A good professional 16mm scan will run you about $500/hr at a 2:1 flat scan ratio. So, right about $500 for 3 400FT loads of 16mm.
Processing is about 20 cents per foot. So, 1200FT would be about $240.
$240 - processing
$400 - (approximate) for film
$500 - (one light, flat to Prores 4444 or DPX)
Give some error and figure $1200 to $1300 should get you through. But, you should be able to reduce cost considerably with good planning and rehearsing. I'd say This is a very high estimate.