Kids happiness doesn't based on how much you spend for their toys, it is based on how you spend time with them. You don't have to spend a lot of money to buy them expensive toys just to be happy, your presence is what makes them very happy.
I was telling my kids about my childhood one day. I told them a story about us not having money to buy a real balloon so what my mother would do is get a n empty plastic bag and would blow air on it then tie it. Then we would have so much fun letting it bounce from our hands.
Children needs the presence of their parents especially on their young age. The more time you spend with them, the more happy they are.