Bro, medyo mahirap explain tanong mo. Magstart yan sa internal parts ng DSLR of course. CMOS/CCD, LCD, Processor/Procssing Engine, Controls, Buffer (RAM), It woks much like a computer.
Imagine. It's works jus like a typewriter. CMOS/CCD=Printer/Ink, Bond Paper=Film/Memory Card, Keyboards=Lens(input), Buffer=Margins, Books/published material=Pictures printed(output)
Regarding Economy, It's your choice where to start naman. In my opinion, you don't have to start of with film since Digital is already cheaper, though it CAN be more expensive.Try to sort out what your needs are then invest in really good equipments. Kung bibili ka kasi ng film, by and by you'll want to move up to digital. So why not invest in digital right away? Unless you plan to stick or keep a film camera for untouched prints. For the record I've been into Photography for 12 years na 9 of which I've done professional works(getting paid) in which I've used 35mm, 120mm and recently digital. Never thought na ganun kabilis ang magiging transisition ng demand and technology.
Paano magiging mahal ang film? You have to buy film of course. have the film processed and printed. If you wanna post process the film, you have to paint brush/hand paint it. Or, scan and edit into a PC/Mac w/c will take up more time and electricity in the long run then have it printed again losing some faithful and important details.
Paano magiging mahal ang digital, you'd want a better digital camera one day. You'd want better lenses same as film photography. You'd want a better and faster PC/Mac. You'd want to have more software to play with. You'll be spending so much time in the computer and electricity bills soar. On the brighter side, you can practice more with digital photography as much as you and your equipment can handle which really improved my photography even more.
I believe that lack of discipline should be blamed on the person not on the equipment. Tayo naman ang pumipindot at di tayo ang pinipindot ng cam. Remember, noong unang nauso ang 35mm(Back then 4"x5" or bigger films are more popular), dami ring natuwa na photographer dito kasi mas mura at capable sya. Therefore, dami rin nilang naaksaya sa tuwa nung "new technology" pa ang 35mm film.
Haha.. Not discouraging you my friend. But that's the reallity of photography, magastos either way kaya nga ako natutuong rumaket sa photography starting at the age of 17.
My advise is what ever your needs and preference (and budget of course!) is, go for it.
Cheers.