I was looking for a high speed cutter at HD this week, which they don't stock as a separate item as it turns out. However, I did find this tool kit reduced from $29.xx to $22 on clearance which did have the #191 cutter I needed. It's not listed on HD's website anymore, but I found the kit at this link. Add the Lowe's coupon for $20+tax out the door.

Since one of the cutters is around $5, it's a decent price for this many accessories. The only place I could find it otherwise was a strange link at Amazon to some vendor which wants $89.99 plus shipping.

It has quite a variety of cutters, sanders, grinders, etc., for the Dremel, and the case can stand upright or be attached to a tool board. There's a spot on the bottom where you can insert a smaller Dremel storage kit, but I don't know which one fits. It has an EZ Lock bit changer to make swapping bits faster.

I think they've been sitting in HD for awhile because they were quite dusty when I pulled a couple off the shelf. I found them at two different stores in the area, but I suspect availability is fairly limited.