Wedding party make up

I would give them the option. Tell them they can do their own, use your artist (maybe send them her website or instagram or something) and tell them the cost, or suggest you hire another artist for cheaper. If they are paying for it I assume they will just do their own if they can't afford your artist. Most HAMU artists I talked to wanted a minimum of 4 girls to travel.

Definitely agree that you should check with any HMUA you are interested in - many have a travel minimum. Bring up the budget concerns with them as well. If there is a second person they work with (apprentice, slightly less experience, etc.) who charges a little bit less and will not be affected by the travel minimum, that may be an idea.

Either way, I would say that's nice for you to consider their budget. Consider making hair & makeup optional - some may want to use your artist regardless of the price, and some may just opt to do their own.

Check with the HMUA you want first, especially if you are requiring on-location services. I had to add more people because they did not travel for less than 5 people and I have a very small wedding party.