Children are 5 and 7. Both have December birthdays so we are drowning in toys. They both got a toy shop voucher from an aunt that they are desperate to spend.
My view is that it is their voucher to spend on whatever shite their heart desires. I'll offer opinions and guidance but ultimately it's up to them. DH always wants to basically choose how they spend the voucher with some small input from the kids and definitely prevent them from buying crap.
I think it's much nicer when they can tell the aunt what they bought and why they chose it etc rather than having their options being heavily restricted.