The price of infant milk powder has skyrocketed over the last decade, increasing 120 per cent to $56.06 on average for a 900g tin.

This outstrips the price increases of other dairy products and household staples over the same period.

A baby can go through three or four such tins a month, which means families can easily spend around $150 a month on milk formula.

Milk powder companies attributed the price hikes to research and development to improve formulas, and rising overhead costs.

But economists say it boils down to the inelastic demand for such a product. This gives suppliers the upper hand because parents are willing to bear such price increases for their children as it is an expense for the short term.

The market for milk formula here grew 17 per cent to $203.4 million over the last five years, and is projected to increase further to $209.2 million by 2021, according to market research firm Euromonitor International.

Some parents have cut costs by buying formula from Malaysia, where cheaper prices and a favourable exchange rate mean savings of up to half.

Pricing differs from country to country as factors such as operation costs and taxes vary considerably, said some milk formula companies.

The Health Promotion Board encourages breastfeeding exclusively for at least six months, followed by the introduction of solid foods and continued breastfeeding for up to at least a year due to its health benefits for the baby.

But for some mums, this can be a difficult task.

According to the last National Breastfeeding Survey, the top reasons that mothers cited for stopping breastfeeding were an inability to supply enough breast milk and the need to return to work.

It is the families for whom infant formula is a necessity that the price hikes hurt the most.