Dusty,
As Flash said, the $38.95 is for the conversion kit. This consists of the shell plate, (the equivalent of the shell holder on a single stage press) 4 locator buttons and the appropriate powder funnel. Check the cartridge drawings in your reloading manual to see which shell plates can load multiple calibers. My .30-40 Krag uses the .44 magnum shellplate, the .45 auto serves the whole .30-06 family, the belted magnum plate works with similar belted magnums, etc.
If you can share shell plates between calibers, all you would need to buy separately is the correct powder funnel. This powder funnel reciprocates inside the powder measure assembly, actuating the measure itself, and providing the case mouth flare, so you need the correct one.
The tool heads go for $13.95, and the powder die for each is $7.95. The powder die is what the powder measure mounts to on the tool head. The powder die adjustment is what sets the correct amount of flaring on the case mouth.
All of this sounds more complicated than it really is. When changing calibers, the thing that takes me the most time is re-adjusting my powder measure, and it still only takes 5-10 minutes for that part of it.
Once you have learned the new equipment, and gotten comfortable with it, you can load 400 handgun rounds in an hour. Whatever time taken for the caliber change is easy to make up.