1. The best source of BW film is freestylephoto.com.
Look for its house brand name. It's usually OEM of the best films in the market, whether Ilford, Agfa, or Fuji, etc.
You might find expired film from here, go for it. It's used to be very popular, but freestyle now rarely sell expired stuffs.
I'd not take expired film from any other sources. Not that they are bad, but just I've never heard any good word yet.
2. Developing color films is very easy, but you need Jobo rotary drum setups. It will be very cost effective in terms of per roll,
but it tends to push you shoot a lot more in the short amount of periods. So the cost per month may go up.
A E6 in 1Gal or 5L volumn costs about $80, which can handle roughly ~40 rolls if my memory serves right, But it's better to use up within 3 months.
Check if it makes sense for your shooting quantity.
3. B&W darkroom costs is extremely low,call it zero.
For example, a $10 Rodinal can develop hundreds of rolls, and its shelf life is almost forever. Similar to a 0L PMK or Pyrocate-HD (~$40).
But,perosnally I don't like to scan the B&W. Maybe I'm lack of knowledge on this, but I can't get the looks I'm looking for. I can only get it from chem-prints.
4. For a cheap and professionall grade scan, look for Leafscan 45 or Polaroid 45 format. These are for 120 and 4x5. The price is dirt cheap, usually runs from $200~$600.
If you bump into $200, get it immediately, but even if it costs $600, still a stealing deal. Hey, you don't work for wallstreet, do you? you are looking for good ROI, right?
5. If you reallyends up getting a cheap and good scanner, be careful then.
Cause' you are going to hunting around for the good and cheap wet-mount stuffs, which can get you both crazy and exciting.
I'm sure you are going to post a lot of questions on how to best scan.