#1
which mic should I buy? I basicly only need the mic for vocals and for my acoustic-electric guitar, I have the TASCAM DP-01FX and I would like to record there..
#2
how much money do you have to spend on a mic?

I'd recommend a Neumann TLM 103. It's a fantastic vocal mic, and can do a really good job of acoustic guitars. Of course, it goes for about $1000, and that might be a bit out of your price range.
#3
Anything by Neumann is going to be excellent but expensive. Someone sooner or later is going to mention the MXL 990. It's only about $70 but is insane. Good starter mic.
I was once heavily prominent on these forums from 2004-2007, let's see how long I can stay now that I'm back.