actually, inexpensive film can be found, a bit harder now but it is still possible:
Cheapest source: roll film. ie. you roll your own cassettes form a bulk roll of 100 feet film. Each 100 feet is around 18-20 rolls of film. Of course, the savings in film cost is offset by the time it takes to roll film plus the additional costs of film cassettes. I like the Freestyle Legacy Pro 100 in 100 feet as well as Double-X in 400 feet bulk film.
Ready made roll, cheapest is either Freestyle Photo or Ultrafine Online or Uniq Photos. All online, and google will get you there. I like the Ultrafine price of the Agfa 100 private label as well as the B&W C41 film (comes in odd 27 exposure) cassettes. I like the Freestyle selection of film and the general affordability of film. For Uniq Photo, certain selection are cheaper, eg. Arcos 100 in 120 format.
There are china made brands, but I have had issues with spots and stains which I can only explain as temperature variations in processing or storage.
hope this helps
raytoei
ps. Private Label brands are:
Arista EDU: Fomapan
Arista Premium: Tri-X or Plus-x depending on box speed
Ultrafine Extreme 400 in 120 format: I use HP5+ time for development.