Shooting night scenes with film means you need to light. Fortunately the only two things to stop you is how fast the lens is you are using and what ASA you use. There is no need for gain or a "large CCD size" to compensate as is necessary for digital cameras.
That said, if this is your first short, you may want to do it on super 8. This is the less expensive option of film, you can shoot a higher ratio than if you shot it on 16 or 35 (which means you can try different things with lighting and exposure).
However, shooting on 16 could work just as easily with a Krasnogorsk-3. It is non-syched which is its major downfall (and it only takes 100ft daylight spools not 400's like the higher end 16mm's), but the lense that comes with the camera takes beautiful picture, and the camera mechanics itself are actually really good (picture is as steady as a rock if you load it correctly). I have a k-3 and if I was only going to shoot MOS (w/o sound), I would not hesitate to shoot a 16mm short on it, not even for a moment. But once again, s8 is cheaper, is easier to load (takes cartridges so theres very little room for error), and still gives you that "film" look. A few users here are well versed in 8mm so they would be able to help.
But then for post you have to consider what you want to do. Do you want to transfer it straight to video and cut it on your computer (probably the BEST option although it is an expense that needs to be considered as it could cost from $100-$500 depending on the length of your short). The other method that is more inexpensive but I personally would not recommend is cutting it by hand the reallly old fashioned way. The last method which doesnt sound like it would be in your budget would be to go the more pro way and conform the neg - this is costly because you are now enlisting the help of a post house.
Considering this is your first short, I would shoot s8, buy a few small lights or worklights, get it telecined and cut it on your comp. For a 5min MOS short with a 5-7:1 ratio you might be able to do it for $200-$400 including stock, process, and telecine.
Doing the same thing with a k-3, you might be looking at a $350-$600.
Please note, without knowing what your short is, how many setups you will do, etc. I can't give you an exact amount. It may very well cost less than this.
Dont forget to budget for other things like feeding the cast and crew, film festival entry money, money for fliers and such to promote your short at a fest if you get accepted, etc.