Budget for souvenirs on a trip.
Souvenir spending drifts because it happens in small amounts across a whole trip. Splitting it into a daily allowance for yourself and a fixed amount per person on your gift list gives two limits that are easy to hold in your head at a market stall. The per-day average is the figure to sanity-check against the rest of the trip budget before you leave.
Souvenir budget
Total = trip days x daily allowance + recipients x budget per gift; average per day = total / trip days
A daily allowance of 10-20 units of local currency covers most trips, plus a fixed amount per person on your list. Set both before you travel — that is what stops market-stall drift.
Yes, and they are usually the most expensive per item. Reserving a slice of the gift budget for the airport is more realistic than pretending you will not buy anything there.
Heavy or bulky souvenirs can cost more in excess baggage than they cost to buy. Consider shipping or choosing smaller items when the allowance is tight.