Pulled 6 off the dog tonight.
What’s the best bang for the buck for dog tick prevention?

Permethrin
Buy a bottle for horses at Tractor Supply, mix with water in a spray bottle. Much cheaper than buying aerosol cans.

I have been using Credelio, a prescription-only chewable for about ten years now and it's the most effective preventive I've found. it won't keep the ticks off but will keep them from biting. It works great at keeping fleas off.

It's supposed to poison fleas and ticks that bite the dogs. But I think the fleas and ticks can sense the ectoparasiticide in their blood and it prevents many from biting. I could be totally wrong but I never find fleas on my dogs while using Credelio. I do find lots of ticks while upland hunting in the fall but none are ever dug in.

Don't know about bang for your buck but best I've found is next guard no tick or flees at all on my hinting dogs that live in the house. It's pricey for 3 dogs but worth every penny.