FWIW, I've just plugged the price for Ilfosol 3 into my cost spreadsheet, and I see that it costs $0.23/roll for 1+14 use, or $0.40/roll for 1+9 use. (This is based on the price at B&H for a 500ml bottle and a rough shipping estimate to Rhode Island. Costs elsewhere may differ, of course.) This compares with, for instance, $0.18/roll for Rodinal 1+50, $0.30/roll for ID-11 1+1, or $0.30/roll for Kodak XTOL 1+1. So Ilfosol 3 doesn't look particularly expensive compared to other common B&W developers, unless maybe you're using it straight (undiluted) or if I erred in entering my data.
If US$0.23-$0.40/roll (or equivalent in your local currency) is too pricey, you might want to look into mixing your own developers. You'll have a fairly heavy initial investment in ingredients and a scale (maybe $50-$100 total), but costs will drop a lot, depending on what you mix. By my calculations (using prices from 3-4 years ago)
Dead Link Removed cost $0.13/roll and $0.04/roll, respectively;
PC-TEA is $0.08/roll;
homemade D-76 is $0.12/roll; and
homemade Rodinal is about $0.06/roll (but there are several variants, ranging from $0.02/roll to $0.10/roll).
That said, I don't think cutting costs is that great a reason to mix your own developer; the up-front costs can be substantial, compared to paying $10 (or whatever) for a bag or bottle of developer, and you'll invest enough time in it that the cost savings will be wiped out, assuming your time has any monetary value at all. IMHO, mixing your own developer is most reasonable if you want to try exotic developer formulas or if you want to experiment or learn about developer formulation. Developers can also be hard to come by in some parts of the world, and some formulas (such as
paRodinal) can be mixed from relatively easy-to-obtain items). It might also make sense if you're
very strapped for cash and can get the necessary ingredients and a scale inexpensively. For most people, though, saving $0.10-$0.30/roll just doesn't seem worth it.
