Digital BW, The Print

I'm new to B&W printing and I'm looking forward to Amadou's book. In 
the meantime, I have an Epson R2400. When I use the ABW I get great 
B&W prints, but it's not the same as I just converted on the screen. 
Do I need to use the 'color' function for those particular B&W's? I'm 
wasting a lot of expensive paper. Will the printer print B&W from any 
old color image that is not converted? Did I waste my money and time 
on a B&W conversion plug-in for Photoshop?
Thanks,

Debbi