When I searched this topic out myself, I did the math.
The MM penmakers kit comes with 2" x 2" pads for $9.99.
Woodcraft sells that same/equivilant kit for $15.75. They also sell a kit with 3" x 4" pads for $22.99.
I bought the 3"x4" kit, and cut the peices up into four sets of 1.5" x 2" pads. Seemed like a much better deal as I got four sets for $23, instead of one set for $10. It isn't like you use the whole pad at once anyway. All you need to use is just the corner, then cut it off when it wears out, and that lasts a while (still on my first set).
After buying my MM, I stopped by a Johnson's Workbench (appear to be associated with Rockler), and they had the same set for about three to four bucks cheaper. I just found it on Amazon for $20.
Lately, I don't even use the MM. My last seven or eight pens have been done entirely without MM, and they shine like glass. I wet sand with wet/dry sand paper up to 2000 grit, and then plastic polish. I also have tried the Beal system, and it works great. As soon as I set up my own version of it, I'll probably use it exclusively. I just got some buffing pads from Harbor freight for the Tripoli, and White Diamond, and found a nice cotton pad at Menard's for the Carnuba wax.
Look at the last few pens I've posted in the SOYP section, and look at the pens that Buzzzz4 posts (he uses the first three pads of MM, and then the Beal system).
here are a few examples of what I accomplished without MM (wet sanded through 400, 600, 1000, 1500, 2000, and plastic polish). An advantage of MM is that you can reuse it. However, I've been using the same 1/2" x 3" strips of wet/dry sand paper for the last eight or ten pens. The only reason I do it this way right now is because I have to mount my buffing pads in my drill press, and I'm too lazy to mess with that when I'm getting these results from the current process. Once I set up the buffing system for my lathe and buffer that I'm working out in my mind, I'll probably forgo the plastic polish, and buff instead as I think it looks a little better.
Don't get me wrong. I think MM is great, and it doesn't take but about five or ten minutes to work through all the grits. Just trying to find a better mouse trap.