If you order from Wood n Whimsies their November coupon savings is $2 off on a $25 order. Use 2OFF at checkout time.
On the bushings, if you are good with calipers and know what you are doing making pens, you can get by without the bushings. If you are new, I would recommend spending the few dollars, it can be cheaper and a lot easier than screwing up a few tubes during the learning process. Or you can learn how to turn between centers with custom bushings and forget about buying a mandrel. I also would recommend spending some time on IAP, they have all kinds of info, spend some time reading and taking notes. Some of them are professionals, they make a living making and selling pens.
Marvin