I doubt many B&W fine art printers are going to take their work to Costco.
As a superior alternative, B&W photographers who want the best and most lightfast output, as well as lowest costs, might be interested in the "Eboni" carbon printing options for Epson wide format printers. From the 7600 up, all of the 6-ink printers are compatible with this approach. It's for matte paper only, but that includes Arches watercolor paper. Used Epson wide format printers are readily available.
My latest project is the 9800 -- see
http://www.paulroark.com/BW-Info/9800-Eboni-Variable-Tone.pdf My workhorse for the last several years has been the 7800. See
http://www.paulroark.com/BW-Info/7800-Carbon-Variable-Tone-2015.pdf For many photographers who want the classic 16x20 format, the 3880 is nearly ideal. See
http://www.paulroark.com/BW-Info/3880-Eboni-Variable-Tone.pdf MIS Associates sells the pre-mixed inks. I mix my own, which drops the price almost 2 orders of magnitude from the Epson prices. Any former darkroom B&W photographer is going to be comfortable with DIY mixing. Ink cost becomes irrelevant, and the prints are superior to ABW.
As an aside, I might add that the Eboni-6 inkset resulted from a project I did for a Guggenheim award winning watercolorist who wanted a "workable" carbon inkset. The idea was to make a carbon inkset that would print well on watercolor paper and not have any binders in it, so that it would be able to be smeared on the paper. The project "failed" from the watercolorist's perspective; the raw carbon would not smear with water and brushes. The tiny carbon particles simply buried themselves in the paper's surface and would not move. However, the project produced an outstanding B&W matte paper inkset. No binder means no clogging. True, if the MK dries on the head, it'll cause a clog like any other MK. However, the dilute inks virtually never clog. There is no "glue" to stick them to the head.
FWIW,
Paul
www.PaulRoark.com http://www.paulroark.com/BW-Info/