Re: Can you recommend a cheap mic?
If you don't like the idea of sparing some for an SM57 (that is, obviously the good solution) you might want to try the AV-JEFE N1900 mic. It is rugged, reliable and has the same neutral (e.g. good) sound, slightly below SM sound quality, for half the price.
+1 for SM57 stories: a techie friend of mine mixed a band this February and when he mounted the PA stuff one of his gadgets (maybe a mic or DI box, I don't remember) slipped in a small hole on the stage. He needed his gadget back so he had to climb under the non-accessable part of the stage. The huge heavy old wooden stage segment wasn't easy to remove but he is a stubborn man so finally he could do it, climbed down with a flashlight. He said it was like as if no man had entered there before. Down below there was a nice thrashpile of different filthy things had fallen down during the years there in a small pool that was a mixture of water, out-keg beer, some heavy alcohol, vomiting, sweat, urine, perhaps gas and some battery acid and everything in between. You know, the typical below-stage club soup

So, disgusted, he searched in the damp thrashpile and finally dug out his gadget and some rotten, stinking rusty bar that rested there for years, probably. He wiped off the dirt and it was a rusty SM57 that luckily fell into the pile with the membrane and grill uspide so the killer soup could not corrode the membrane. You know what? He just cleaned it, plugged in and it worked...