Akwat Kbrana said:
As someone said (don't remember who), you can conceive of part 1 as a low-budget grindhouse flick that enjoys unexpected success, leading to a higher budget and mainstream distribution for the sequel.
That was me. :) And after some thought, I could see part 2 as a critical success but financial flop, hence the (SPOILER * SPOILER * SPOILER-ish...) cliffhanger ending that will likely go unresolved.