Newbie - dilutions and quantity to process.

You might consider Rodinal developer for film. It's a liquid concentrate used in high dilution, typically 1+50.
The concentrate will literally keep forever, even in partially-used bottles.
People have reported using concentrate that's decades old with normal results.

I've used it for over 50 years, and have always been pleased.
It works best with slower films, but that's all I shoot.

Another liquid concentrate that supposedly has a long shelf life is HC-110.
I've never used it, so just passing on what I've heard.

- Leigh

When you factor in the cost of film and the cost of actually going out and exposing it...

The cost of chemicals is pretty small.

If I drive to SF, 90 minutes away, to take photos, the cost of gas alone is way more than the cost of new bags of every chemical I will need to print every exposure. And I don't print every one.

Tiny, in comparison.

Buy two of everything you need. When you run out of the first one, order another. That way you will always have fresh chemicals handy.

Regarding the HC-110. From the web: Concentrate has long shelf life, but avoid contact with air either by 1/ topping off with cigarette lighter gas, or 2/ filling bottle with glass marbles enough to not have any air in it. Diluted HC-110 destroys in a few days.
Rodinal changes colour slowly when opened but seems to work anyway.

I only process film intermittently so I use Rodinal, whose keeping qualities are legendary. Stop will keep until exhausted and only once have I ever had to throw out a batch of fixer (it went off during a particularly hot summer).

"Diluted HC-110 destroys in a few days."

Not necessarily. When mixed as Kodak recommends, the stock solution may be kept for up to six months (two months in partially filled containers).

Pre-mixed Dilution B (1:7 from stock solution) may be kept for up to three months in full, capped containers; or one month in partially filled containers.

Many of us mix small, one shot batches from concentrate for each session. But if you plan to develop film regularly - more than once a week - it may be easier and more precise to mix HC-110 as stock solution and then into the desired dilution, per Kodak's original recommendations. Mixing small, one shot batches of Dilution B or H is economical for those of us who develop film only occasionally, but the syrupy consistency defies precise mixtures in such small amounts, even with a dropper or small pharmacy type measuring container.

I never liked the grain of film developed in Rodinal, but it does keep well.

I'm currently using HC110. I have had this bottle for 4 1/2 years and is is half empty. I cap the bottle once I have removed the quantity I need then mix the working solution. I cannot tell a difference between when the bottle was first opened and the last time I used it two weeks ago.

Fixer can be used to exhaustion. There is a solution called "hypo check" that you can use to check the fixer or you can snip test. A snip test is you cut a piece off the film leader and put it in the fixer and time from when you first put the film into the fixer until the film turns clear. Double that time for your fix time then when the clear test time doubles mix a new batch of fixer.

Everybody has their favorites, but for a beginner the most basic, dependable, fool-proof developer is Kodak D-76/Ilford ID-11. (They are the same, just with different brand names.) It comes as a powder and it's cheap, under $10 a gallon. Once mixed from powder the stock solution is good for 3-6 months. You can use it straight or dilute it 1:1 if you like but I just use it straight and dump it rather than trying to reuse. I do not recommend saving up a bunch of rolls to develop for the simple reason that it slows down the learning curve. If it's been six months since you shot something, you don't know about the mistake you made (or problems with your camera) until you've repeated them over and over in the meantime. As Richard says, photo chemicals are cheap in the grand scheme of things. As for Rodinal, the concentrate may last. But there was a recent threat here from a beginning photographer who had tried to use diluted Rodinal two or three months after he mixed it and got blank film because diluted Rodinal doesn't last. I would hold off on anything other than D-76/ID-11 until you've learned the basics. It's like starting with a Ford or Chevy, not a Maserati.

I went over to B&H on the Internet. Ok. I'm not in the USA. You guys have it cheap. For us here. 500ml of Rapid Fixer or Stop bath cost us $18US each. A powder developer cost $10US to make 1L undiluted or $35US for the liquid stuff. How many do you suggest me to collect up to process? Obviously i f I was going to use undiluted Perceptol - that's $10US for just 3 or 4 rolls.

Ray, check into places like Photographer's Formulary and see if it's feasible to ship the raw materials to make your own powdered developer. Basic stuff like ID-11 is easy to make and the raw ingredients shouldn't pose any particular problems with shipping hazards.

I don't have a 1 liter package for Perceptol handy (it's somewhere in the closet), but I think most Ilford 1 liter powder developers will develop 10 rolls of 35mm (36 exposure) or 10 rolls of medium format (120).

In your case, ID-11 (or mixed from scratch) and HC-110 concentrate might be the best bets. ID-11 stock solution produces very fine grain results, even with ISO 400 films, so you may not even need Perceptol.

It's difficult to do better than commercially made fixers so you're pretty much stuck with buying either powder or liquid concentrate. The good thing is that it lasts a long time, so it's still reasonably economical to use.

The manufacturer's comments that concentrated liquid fixer lasts only 6 months or so in an opened container is very conservative - in actual practice it lasts much longer. Even when diluted to working strength for film or paper, I've found my 1 gallon batches of rapid fixer last much longer than 6 months. I think the longest I've used a single gallon of rapid fixer diluted to working strength was a year. But I'm careful to mix separate batches for: prints only (don't want to carry over paper dust to film); another batch for T-Max films only (which exhaust rapid fixer about twice as quickly as other films); a third batch for all other films.