how much would i be spending for say about 5 hours of 16mm footage, including buying the film and developing.

5 hours?
Are you actually making a 5 hour long film and/or series?

Probably better to measure in running time than, as I suspect, raw footage.

I have a friend at school who made a 15-20min film on 16mm for around $10,000. Majority of that was cost of film.

The film itself is expensive, and you will want to limit your takes as much as possible.
However, the real expense comes with developing (might be able to avoid some here if you know a take is bad-- if someone tripped, etc.), then the telecine process where the film is scanned frame by frame.
And, of course, putting it back on film then making copies.

Kodak offers student discounts if that applies to you.

Are you a student? If so then students can get discounts, there are also places that sell short ends instead of the full roll, this can be a benefit in cost, when a 400ft roll of fuji or kodak can cost several hundred you can get the same amount in short ends for under a $100, also look around for the cheaper labs and try to squeeze your stuff in at the end of the baths, it's usually cheaper, and if your transferring, try and get a flat transfer so they can just hook it up to the machine and let it roll.

Shooting in film is alot more different than digital production, alot of time and money goes into it. I got the hookups from several people, friends gave me their short ends and I got the film developed for $200, I then got the transfer onto HDCAM for free, its really who you know that will get you the good deals.

Jemore, interesting info. But how long was the film?

5 hours of 16mm at 24fps is about 10800 feet. If you buy in 400 foot rolls, you're looking at 27 cans of film. Figure roughly $200 per roll (without a student discount) = $5400 for stock alone, not counting processing and telecine. Here in San Francisco, the going rate at Monaco Labs is .20cents a foot for processing = $2,160 for processing... call for quotes on one light video dailies.

Now depending on your shooting ratio, that may or may not get you what you want.

Students get discounts from Kodak. Also, I've worked on a 35mm shoot where we picked up a couple of GREAT deals on Ebay. Bought from other production companies and such. Just checked ebay now, and theres a couple of rolls up for sale. Of course, you have to know what you want, or work with what you find.

It really is about shopping and working deals, talk to labs ahead of time, big savings can be had.