Digital BW, The Print

I'm currently evaluating three of the new fibre papers (I like them
all!). But as they're quite pricey, I'd like to find a less expensive
paper for day to day proofing that uses the Photo Black cartridge in
my R2400. Swapping out the black carts for my normal matte proofing
paper is unacceptable. (Not to mention, matte paper does not tell me
how a print will look on the semi-gloss papers.) 

BTW, the three papers are, from highest to lowest cost, Hahnemuhle
Fine Art Baryta, Innova Semi-matte, and Ilford Galerie Gold Silk
Fibre. In case anybody wants to know, here's my take on them: 
Ilford: best value, warmest white, smoothest surface, ink appears to
sit very slightly on the surface. 
Innova: Slightly blue, least bright, smooth surface with
unobjectionable texture, curls at edges a bit; my favorite, but just
slightly and only if cost is ignored. 
Hahnemuhle: bright neutral white, very saturated, slight luster
texture that shows up when the light isn't just right, ink sits down
in the surface like a silver print, expensive!