My beloved HP5+ is hardly the least-expensive film on the market. I also like Ilford’s Kentmere 100. At ~$70.00 for a 100-foot roll, it costs just 11 cents per shot. Freestyle’s Arista EDU film costs $51.99 per 100-foot roll—just 8 cents per exposure.
Bulk rolling has advantages beyond costs savings. Chief among them, you’re not stuck with 24 or 36 exposures. When I buy a used camera, I don’t need to burn a whole roll of film to test it out; instead, I’ll whip up a 5-exposure test roll. For general use, I load around 25 exposures per roll, though this does increase my development costs slightly, as you’ll see in the next section.
What about equipment? You’ll need film cassettes, which sell for around $1.25 each. They last for years, making their per-shot costs basically negligible. Some photographers use a bulk loader to wind film onto the cassettes. A loader costs around $50, and if you only keep it ten years—chances are it’ll last five times that long—it’ll add about a third of a cent per frame to your film costs. Me, I don’t use a bulk loader; I simply spool up my film in my dark bag.
Source : https://www.popsci.com/diy/film-photography-save-money/