Just book a party and call it a day. This is not that big of a deal. Invite the whole class or all the boys. Not everyone will come. Pick activity loved by your child. We have done laser tag, science party and this year, we are doing launch. We have a lot of family friends so I like parties that can accommodate a lot of people.

Until second grade, I would say many did entire class invitations. Venues at laser tag or the various tumbling places will come under $1k even if 25 kids attend. Depending on how convenient or inconvenient the time is, you will get a turnout of at least half the class saying yes to a party at that younger turning 8 age.