I bought one from a local dealer. They sell a nice metal one. I also bought one cheaper at LongCreekMills. I was placing an order there anyway for some Stiffy and picked up a second one to use with my embroidery machine... It's also a nice, metal one.
My local Hancock's and Hobby Lobby sell a spool stand/mast and it is really cheap. It's solid plastic. I would not waste my time on it.
You can also make your own if you are inclined. If you do a google search on how to make a spool stand, there are lots of ideas. A friend of mine uses a coffee mug & a suction cup hook on the side of her machine since she didn't want to spend the $10 to buy one at the local store... It works well enough for her :)