I usually use $15 as the rule of thumb for the birthday parties to which my kid is invited. Sometimes I go slightly higher or lower but that’s the general rule. Across the board. I let my son pick out the gift because he goes to school with these kids and knows what they like, and we can usually find something reasonable in the range.

We also reuse the gift bags that have come from other parties. Once in a while, I’ll buy an assortment pack (from a school fundraiser) to have on hand.

The “in lieu of gift, please donate to xyz charity” idea seems a little weird for young children. I completely understand the merit, but it doesn’t make for much “fun.” I’d rather say “no gifts” than designate a specific charity.