Francesco,

You may wish to review the write up on paper developers for AZO by Dhananjay Nayakanakuppam found on the Unblinking Eye.

http://unblinkingeye.com/Articles/Azo/azo1.html

His curve data seems to indicate that Ansco 130 with Glycin has a very similar curve shape to MS's amidol developer. I've not had a chance to try it yet but by my calculations the 130 formula could reduce developer cost by 50% or more per liter of working solution. AFAIK, Photographers Formulary are the only sellars of small quantities of Glycin.

It's not clear to me what the tray life of Anco 130 would be as compared to Amidol developer and the effects of water bath development as compared to Amidol.

Hope this helps,

Don Bryant