What do you mean by "containers"? Do you mean breeding tank, or housing tanks, or containers for grown up fry?
You can get a 10 gal breeding tank for $10-$15 at the LPS or you can use a cheap plastic tub like a lot of ppl do but it's so much fun watching them spawn... glass tanks allows all the details to be visible!
Foster and Smith aquatics website has good prices... I got most of my things there (e.g. sponge filter, heaters, air pump, etc.)
For fry containers, the beanie baby boxes are very popular. You can also look into glass jars but they are a bit more dificult to clean and, of course, heavy!
Also, some people use 32oz deli containers which come with lids... lids are important!
I found this website a few months back and it has good information...
I think the medications are an overkill if you're not on top of your water quality and you can definitely subtitute some things for others but the way she describes betta behavior during spawning using pictures is great!
is another great source of info.