1. 20-40 bucks
2. Depends how potent your eighth is and how well you handle psychadellics. Could go either way. Just don't do more then an eighth for your first trip and you should still be functional and not whacko.
3. 5-8 hours.
4. Disassociated, mood-lift, reality seems to have more of a "pow-bang" effect to it. Like reality hits you harder. Trees are prettier, flowers are brighter, rain is drearier and more malicious feeling, etc. A lot of people have no hangover effect that they recognize.

Good luck. I hope you do some.