Hobby / splurge money

Need to settle a debate with wife. Mid-30s and own home with mortgage. Between us our income is about $180k since wife is only part time at the moment with young kids. Life’s generally ok financially speaking.

Retirement planning is going fine, only real financial goal outside of that is family holidays and setting kids up with house deposits in 25 or so years.

I have hobbies, interests etc outside of family interests. Wondering what’s a good budget for me to splurge on my hobbies, interests, gadget in this context?

This money would be outside of family splurge money that we spend together and outside of personal needs. This wouldn’t include personal necessities like clothing etc but will include stuff like takeaway lunches etc.

Is there a % that’s considered reasonable?