How much $ for bridal party proposals?

Can you take them out top lunch and simply ask them? Why the need to propose to them? They might feel out on the spot!

I am doing boxes with a little ask card that I designed on Canva. Each box will cost about $20 toal. Each girl is getting a clear coffee mug with a monogram of each girls last name on it. Then a rose gold scrunchie and an aromatherapy candle. My junior bridesmaids (future nieces), are getting color changing cups and a card, and my flower girls (future nieces) are getting little sunglasses in the shapes of flowers. So all in all I am spending $100 on the 7 people in my bridal party!

Still looking around for candles/boxes that might be a better deal though!

The cost and time of a phone call or text. The ladies I'm planning to ask are scattered around the country and aren't the collectibles type and chatting would be more sentimental to them than a tshirt or mug.