I've not used Somerset Velvet, most of my matte work is on VFA or USFA, so I'm a little confused when you talk about a "non-textured paper fine art velvet paper". I'd suggest you look at the big picture:
Are you selling your prints? How many? Is $1.40/print really going to make a significant impact on your bottom line? So you buy a D-Roller from Shades of Paper for $249, a roll of Somerset Velvet for $130. You get $50 off the D-Roller with a roll of paper but the roll of paper costs $10 more than from B&H. So you've netted out at a $40 savings. At $1.40/print, you'll have to make 149 prints to amortize the D-Roller, over four rolls of paper.
So now you've broken even on the D-Roller, but what about your time and effort? How long does it take you to cut and uncurl 250' of paper into 17" sheets? What's your time worth?
I'm not saying it's a bad idea, maybe you prefer the Somerset over the VFA and that's the only way you can use it. Or you just want to try it out. If so, more power to you. But your post suggested that you were interested in cutting costs, just be aware that there are more costs than buying the paper.....
And what about USFA? Rolls are a lot cheaper than the Somerset.....
Just my $.02 worth,
Bill