I have started recentely with 16mm and believe me, it does not need to be expensive. You can get short ends very cheap: www.drrawstock.com and also, if you do the processing of the film by yourself (i have a rewind and a spiral tank and the spiral produces much nicer results without the pain of rewinding it), the costs become really low. I first started with super 8 (using a Nizo 560 that costed 5 euros on ebay). Great camera w time lapse, different fps. Then I bought a K3, also with single frame and different fps. I did an intervalometer for it using an electromechanical solenoid and now I am in love with my Kinor 16. Short ends as I mentioned are cheap and they are the way to go if your budget is limited. Also, check Orwo BW films (www.dakan.dk). It costs ~70E for 120m. Great results.