For the 357's, the Lee Classic is hard to beat. That's the little kit that you smack with a mallet or a block of wood. They usually cost around $16.00.
For the shotgun shells, a set of Lee dippers ($8.00) and the rest of the stuff (wads, shot, primers, powder) Place theempty shotgun shell over a socket from your tool box, use a nail to punch out the old primer. Place a new primer on the table, use a dowel and a mallet to carefully to drive the shotgun shell down onto the new primer until it's seated. Use safety glasses here!
Use the Lee dipper to scoop the appropriate amount of shotgun powder into the hull, jamb the wad down into the hull and tamp it down with the dowel. Now fill the shotgun shell up with shot until it looks about right. Use another socket to squash the top of the hull down, the use whatever to force it on down into a nice looking crimp.
You can also cut the very top of the hull off (the part that crimps over) then glue a piece of cardboard or an "overshot" wad into the end of the hull. I've used waterproofwood glue or "fletching" glue that you can buy at the archery supply shop.
Total expense to load shotgun shells, around $10.00 or so, although this works best in double-barrels or single shots. Works OK for pump guns too. Autoloaders tend to prefer a resized hull to feed properly.