The pharmaceutical companies aren't interested in developing inexpensive drugs you take a few times and then are done with. They want to develop something you have to take for the rest of your life to treat a chronic condition and charge as much as they can get away with.
Bzzt. This is a very common misconception about the motives behind pharmaceutical companies not going into antibiotic or vaccine research without government funding. It doesn't hold up to scrutiny.
Any competent pharmaceutical company is constantly looking for cures to both acute and chronic conditions. Why? Because not only would it be a very expensive drug that you take a few times while the patent is active, but when one company discovers the cure, all of the other companies are left holding their dicks in the wind. No company wants to be in that position, so they all want to be the first to a cure even if they technically would make more money with a non-curative treatment in the long run. It's the Prisoner's Dilemma writ large.
Funding for antibiotics isn't low because Big Pharma doesn't want to cure people. It's low because there's a lot more money in a cure for type II diabetes than there is in a cure for carbapenem-resistant enterobacteria.