Indeed, some morderation is key regarding the amounts of time gifts are given.
If playmobil is given every single week, they might appreciate individual sets less and might see it just as more to add to the pile.
When I was a kid, my parents would often reward good behaviour whenever we went shopping with a little box of playmobil. One of those with a single figure or such. If we where good we received such a little something, if we where bad we didnt get anything. We really valued those single clickies as well since to us, each new clicky brought new play possibilities with him/her.
Of course budgets differ for each family situation, but regardless of budget its good to reward good behaviour, or maybe let them help out a bit around the house or such, so they wont simply get what they want regardless of their actions.
If you want to be funny about it you can reward your kids with a playmobil gardening set after they helped you out in the garden for a week.
