What is Upkeep ?
Upkeep is noun 1. the cost and pro- cess of keeping property such as a house, garden or car in good order We’re forced to sell the house because its upkeep is so expen- sive. I’m responsible for the upkeep of the garden. 2. the cost of paying for children’s clothes, food, etc. Their father is supposed to pay for their upkeep. How much are you getting from your ex-husband for the upkeep of the children? (NOTE: no plural)
source: Easier English, Student Dictionary Upper Intermediate Level