A tube of Soolantra last longer than you would expect, when using a small amount of it. Like a few months. If the price of Soolantra/Rosiver (topical ivermectin) is a problem, you could try a topical animal form of ivermectin: Ivermectin for horses/animals Multiple people get similar results with it.
But some researchers are reporting that ivermectin gives positive results in fighting against the coronavirus in vitro: https://en.wikipedia.org/wiki/Ivermectin#SARS-CoV-2
But the effective dose may be way too high to be suitable for humans. If ivermectin (used orally) turns out to be a good candidate as a COVID-19 drug, then the availability and price of ivermectin may change significantly. The high price of Soolantra/Rosiver isn’t caused by production costs, but by patents if correct. And this price differs widely per country.