HC-110 used 1:63 (dilution H) will save you money over D-76, and give close to the same results as D-76 1:1. If you only mix up small amounts of stock as needed, the syrup will last forever and be dead-on consistent. You can get very close to 100% use of HC-110 if you do not mix it all up at once, no matter how long it sits. (Even the stock lasts a very long time in half full bottles.) It is this that gives it the economy advantage over D-76, not the calculated actual cost per roll assuming 100% use (which is actually lower for D-76).
Kodak Hypo Clearing agent is very cheap: Under $3 per quart of stock. The stock is diluted 1:4 to make a working solution that lasts a day. This is enough to let you do five days of processing if using a one liter tank, 10 days of processing if using a 500 mL tank, or 20 days of processing if using a 250 mL tank. Therefore, the more batches you do per day's-worth of working solution that you mix up, the more economy you get. I try to do at least two one-liter batches in a day when I sit down to process. That way I use the entire 250 mL of HC stock (the minimum I mix at any one time), and I get some extra money's worth out of the daily batches of HCA and Photo Flo.
Vinegar for stop bath won't save you any money worth mentioning. Just stick with Kodak Indicator Stop Bath or something like it, filter it as you pour it, and use it to its capacity. As it is right now, I am spending about a dollar a year on Indicator Stop Bath by using it not even to its capacity. At my current rate, I will have had my bottle for about 8 years before I need to replace it. I think it cost me six or seven dollars...and I know exactly when I need to toss it, because it turns purple...no guessing.
The price you are paying for the Ilford Rapid Fixer is a good price. I buy it for $10 a liter because it lasts long enough for my volume of use, and I don't want to deal with the big container of it. Those five liters of Rapid Fixer concentrate give you 25 liters of film fixer working solution for $22. Not bad, if you ask me.