I've heard good things about the
Paizo wet/dry erase maps. I haven't used one, but considering the amount of people that use it, I think they're on to something.
For the pieces, might I recommend just using tokens?
Here's a tutorial on how to make some 1" flat tokens, it uses
TokenTool which is easy to use and you can make your own tokens using whatever art you want and print them out. Google Image Search will be your best friend when making some encounters. This is what my current GM does for our 4e games, though he has some rubber type thing as the base for the tokens, I don't know what they are, though I can ask him. He doesn't use a lot of glue so they remove easily and are reusable. Maybe pick up some isopropyl alcohol so you can remove the paper and glue residue much easier, since it is a great solvent.
My GM uses the printer at his work to do this, so it doesn't cost him anything. If you want to cheap out, you can always just print out tokens with generic words on them: Minion, Human, Monster, etc. Then number them for damage reference: Minion 1, Human 1, Monster 1, Minion 2, etc. This way they're reusable and players can just use their imagination.
As for dice, I'm not too sure. I bought a lot of mine from
The Dice Shop, which is in the UK;
GameStation would probably be better for the US. I use GameScience dice, because they roll a lot more fairly than others, but that's a whole other topic of discussion. I buy them uninked and just ink them myself with a Sharpie or a paint marker according to the
GameScience colour chart. They're probably not what you call "cheap", but I think they're worth it. Since you're after the cheap option and I'll assume you're looking for some dice "for the table" so everyone can use them, you could always grab a
Pound-o-Dice from Amazon or another retailer, it should give you enough dice for a few people, otherwise just look around for "Chessex" dice sets which should come in your standard packs with 7 different dice for about $5+.