Digital BW, The Print

Could someone explain what the advantages of this printer are over the
current R1800 & R2400?  

How expensive will the UltraChrome High Gloss 2 inks be?

Is it likely that the R1900 will be better than the 1800 for B&W
printing on matte papers?

If so, I'd consider getting it.  The one major thing I don't like
about my R2400 is having to switch out the PK & MK cartridges for
glossy & matte paper.  If I could have a printer that handled B&W and
color very well on both matte and glossy papers, with no switching of
cartridges, that would be the one for me (assuming said printer costs
less than $700).