You can start at level 1, but you shouldn't unless you don't want to use other methods to skip the early levels, such as making sulphurous fertilizer or planting trees, until level 32 when it becomes quite profitable
I've added something to increase the prices slightly on those items, above the prices it receives from online sources, but this can't guarantee success on rarely traded items - there may be cases where even if you offer 100 times the market price, there will be no one selling it, in which case it's best to stop the script instead of trying for hours (there are only a few items like these, and generally cheap ones, buying a large quantity manually before running it will prevent this)