Whew, that JandC and Efke film ain't cheap!! Ok, well, I suppose it's average price, isn't it? Not that I'd pay that much...
Yes, Arista 125 is FP4 and Arista 400 is HP5. I use Arista 400 for my pinhole camera... same film, lower price. Some say it's film from the 'end' of each mass produced roll of Ilford, whatever that means in terms of quality.
Mike - Originally I used Arista OrthoLith (which is cheap!) because during the summer class (photo 101) I took at the community college before building my darkroom I learned of a little secret... the lost and found box. Rummaged through and found the OrthoLith, and the professor said I could have it. I thought it was paper, and was wrong. But it came in handy when I discovered Cyanotypes a year later. I do a test strip at f/8 (I think... my darkroom has been packed up a few months now, for an impending move) for maybe 5 or 10 sec intervals. Speed is ISO 4 if that helps. I develop in Dektol (isn't that handy?) at a high dilution... 1:20 or so. The negatives turn out fine for my personal tastes as far as contrast goes. And it's helpful that the negatives can be processed under red safelight. There's a fair amount of info on this procedure to be had via Google.com. Arista is available at www.freestylephoto.biz ( http://www.freestylephoto.biz/sc_pro...d=406&pid=1190 ) $45 for 100 sheets of 8x10.
When my darkroom is back up and running I plan on experimenting with two different procedures. First is direct positive using negative film (again, Arista Ortholith). This is accomplished by exposing, flashing, and then developing normally, bleaching without fixing, then re-exposing the remaining silver to room light to get a negative image. It requires Sulfuric Acid (easily obtainable and cheap - battery acid or pool acid), Sodium Sulfite (common developer chemical... probably can be had locally in a decent sized city... look for chemical suppliers), and Potassium Dichromate (used in alt. processes like gum bichromate, same as the last, or go to photographer's formulary website or other online supplier). Safety procedures should be strictly followed, btw... hospital-type respirator, goggles, gloves, good ventilation. Seems like this method may or may not be worth the extra work, but chances are it's pretty simple so long as you're organized and have a fair amount of negatives to make at one time. Saves film, as there is no need for an interpositive.
Other option is continuous tone dupe film from Photowarehouse.biz for making direct negatives with standard processing. They seem to have the lowest prices for such film. $25 for 25 8x10 sheets or $82 for 100. http://photowarehouse.biz/pdf/photo.pdf - 4th page, middle left.
So, this is all I have so far, and I hope it's useful. Check the thread under Alt Process forum titled 'Internegative Guide Wanted'. I imagine each process is pretty equal in comparing price/work involved. It's probably more a matter of what each individual is comfortable with. I will probably end up leaving myself two or three options... for days when I'm lazy/can't think straight and days when I'm up for a challenge. Probably will see slightly different negatives with each option also, which may lend themselves to certain processes.
I will start experimenting soon (hopefully!) and will update you if you like.