He walks smaller dogs and sells drinks that he makes at the football field near the house. The neighbour lets him pick lemons to sweeten the drinks. He worked for two years to buy the absolute least expensive phone available. I did buy him a case as a gift for achieving his goal, though: $3 on Aliexpress.
I should mention that he also managed to buy two goldfish during this time - also with his own money. So he learned very well to budget, and that each thing that he buys along the way pushed back his goal.