Also, you don't need everything to be sterile anyways, and pads and tampons certainly are not. Clean is enough, with sterilization from time to time.
Germs which are not even that big of a problem anyways, considering vaginas are supposed to be in contact with dirty stuff : fingers or penises are not known for their cleaniness. It mostly self maintains.
And yes, vaginas are great but any membrane suffers when in prolonged contact with foreign material. And again, access to antibiotics and antifungals is a worthwhile consideration when using small-but-still-higher risk sanitary products.
The general economic problem behind this is common for people living from paycheck to paycheck. For example, a good pair of shoes will last over a decade but cost 100€ (=> less than 10€/year), while cheap shoes for 10€ last a year. Now the cost over 10 years is equal, and for any year the shoe lasts longer, the person saves money. But without access to non-predatory loans (such as payday lending, pawn shops, mafia loans or CCs >5% APR) the person can never realize the saving.
Take boots, for example. He earned thirty-eight dollars a month plus allowances. A really good pair of leather boots cost fifty dollars. But an affordable pair of boots, which were sort of OK for a season or two and then leaked like hell when the cardboard gave out, cost about ten dollars. Those were the kind of boots Vimes always bought, and wore until the soles were so thin that he could tell where he was in Ankh-Morpork on a foggy night by the feel of the cobbles.
But the thing was that good boots lasted for years and years. A man who could afford fifty dollars had a pair of boots that'd still be keeping his feet dry in ten years' time, while the poor man who could only afford cheap boots would have spent a hundred dollars on boots in the same time and would still have wet feet.
This was the Captain Samuel Vimes 'Boots' theory of socioeconomic unfairness."
And that predator lending has now made the next purchase decision even more difficult than the last.