He has it right on this list. With the exception of the priming too, which I would get anyway as it is quicker, you need a dial caliper for your own piece of mind. This allows you to know that the brass and components are the size they are supposed to be.Here's a suggested list of minimum required equipment:
1) Die set for each cartridge
3) Shell holder for each cartridge, if not included with die set
4) Caliper, to measure length of completed cartridge to set correct bullet seating depth
5) Powder scale, either balance beam or digital
6) Powder funnel
7) Case lube (for bottleneck cartridges or if you don't get carbide dies for straight wall cartridges)
8) Loading block to hold cases
9) Powder measure of some sort
10) Reloading manuals
11) Scale calibration weights
12) Case trimming tools (usually not required for straight wall cases)
13) Priming tool, if you don't want to prime on the press
Beyond that there are lots and lots of nice to have items. A good book for beginners is "Things They Don't Tell You About Reloading", more info can be found here. You should have at least one good reloading manual, two is better. A good general use reloading manual is the Lyman Manual, it uses a variety of powder and bullet manufacturers and has a good intro to reloading. For a second manual I like one from the the supplier of the bullets I am using. So get the Hornady manual if you are using Hornady bullets, otherwise almost every bullet supplier has a manual.
For the cost of reloading, you can easily calculate the cost of the components. There are 7000 grains in a pound; for 9mm you should get 1000 or more rounds from a pound of powder and 500 or more for the 357. Add in the cost of one primer and one bullet, you'll find that jacketed bullets are usually the most expensive component. As BigG noted above this is a hobby and you can save money over factory loads, especially for some rifle ammo, but you should also enjoy it or you will lose interest.
Check your powder well as you may find a powder you cna use for 9 and 357. I prefer Hogdons but most powders out there are good. Looks like Universal or Clays would be a good start, depending on what bullet weight and type you are going to use.