I just got started so I can give you some idea. You can get a starter kit
for about $60. This will include a mandrel, a drill bit, a reamer, 5
blanks, CA glue, Hut finish and 5 pen kits. I am a fairly experienced
turner and I was able to turn out good pens right away. If you mess up and
cut one too thin, just glue another piece of wood on the tube and give it
another try. I sell the pens for $35 and I have had a pretty brisk business
without even going to a show yet (I have bought more supplies). I assembled
the pens with a drill press and it was fairly straight forward.

After you get hooked, you will probably want a vise for holding the blanks,
a pen press and an fid for gluing (all for under $100). I also bought a
parabolic drill bit (a dream to use) and many more kits. I also branched
out into another size witch entails a different set of bushings, a different
reamer size and a different drill bit.

I use my standard 5/8 gouge (very sharp) and a standard skew. I did have to
make a small parting tool to cut a grove for one type of pen's center ring
(Father Sing pen) but generally no special tools.

I love it after turning big objects for several years because you can use
the scrap that you normally throw away to turn out beautiful objects.
People really gravitate to them and they like them very much for gifts. I
try to use the local wood here (kamani, ironwood, etc.) to add some value.
I just turned a set over the weekend made from a stick I broke off a tree in
my yard. It has been great fun.