The only ways to get a reduced ticket is to buy it with plenty advanced notice or apply for a low income and scholarship tickets. For ticket info, check with the Burning Man website. (They are currently sold out for 2011. That's what you get for waiting until the last minute! But, tickets are still for sale on Stub Hub, the reason it's sold out through the website, most likely.)
You're essentially going to be living on a desert that has a TON of dust storms and frequent white outs- meaning dust gets everywhere. There are a ton of packing lists available- you can check out my review or go to Burning Man's complete packing list. You don't want to bring food that'll spoil and that can't be stored easily. The easiest options are finger foods, so you don't need to bring plates, etc. Also, overpacking tends to take up too much space in your car and create a lot of waste that you will have to bring back home with you.
DRINK LOTS OF WATER! I can't say that enough. You'll be in the high desert and Black Rock City, the name of the "town" that Burning Man is located has some for sale/barter but, you're going to want to bring enough water to keep you going.
Like I said in #2, there are a ton of white outs here- playa dust is the WORST and gets over everything, even when you think you're covered and your belongings are all zipped up tight. Bring dust masks and goggles, don't forget to zip up your tent and use a tarp as the floor of your tent, don't go barefoot- your skin will have a bad reaction to the alkali lakebed and keep your things in plastic ziplock bags as much as possible.
Burning Man is huge....there are upwards of 50,000 people in a variety of abodes from tents to cars to RVs to camps to communes. It's incredibly easy to get lost. SO always have a flashlight or headlamp, if you have a bike make sure the headlight is working and that you wear reflective clothing, always carry the map, be aware of detailed visuals of where your camp is as well as the "street" name and acquaint yourself with the emergency stations just in case you need them. It's also a good idea to have a walkie talkie, just in case your cell doesn't get service in the middle of nowhere. Make sure you have a double set of keys for your car, you'd be amazed how many people lock their keys in their car and get stranded.
There is a STRICT Leave No Trace policy- as such you are responsible for your waste. Yes, this means EVERYTHING. On the last day, there is a huge clean-up effort to attempt to restore the desert back to what it was before you landed on the playa. Glass, styrofoam, and anything that can't be burned or create a toxicity when burned are all incredibly frowned upon. Make sure you bring enough plastic bags to store your personal trash.
Burning Man is all about community. This is the place where people come to let go and be themselves, without societal constraints. As such, you WILL see everything from public sexual displays to people fully nude or body painted or covered with feathers to people whacked out of their minds on whatever they've gotten their hands on and everything else imaginable. This is not the place to bring your prejudice or stereotypes, no one wants or needs it here. You don't need it. Once you throw that away, it's amazing the people you'll meet and what you'll learn. Trust me, just be sure you throw it in the appropriate trash can or burning barrel, you don't need to take it back with you!
Avoiding theft is a major concern on the playa, especially if you have a bike. It may be that some altered person just thinks your bike is theirs or they look the same and voila- they take off with it. You have no use for your valuables in the desert, leave them at home. If you bring a bike or other form of transportation, make sure you have a locking device for it. You don't need oodles of cash at BRC- just a couple of dollars for ice for as long as your stay. Other than that, the last I checked the only other thing for sale was coffee- I've heard rumors that that's changing but, you'll have to check with their website.
I've heard in recent years that people have been coming to Burning Man because it's cool or the scene and as such, aren't familiar with the true meaning of Burning Man. They have private camps with private parties and alienate themselves from the experience. Hey, I'm all for camping with your friends but, you can do that at some 2 day music festival. Burning is for building friendships and communities. You can't do that if you've red-roped yourself into your own little RV now, can you?
Ahhhh....who to go with? Avoid fighting with friends and ending friendships or relationships at the playa, oh it's happened. Burning Man is a notorious relationship destroyer- you have an incredibly harsh environment, huge crowds of people mixing together on all sorts of substances or dead sober, an openness that's not always easy to deal with and quite uncomfortable at times, different schedules (some people are early sleepers, some need to stay up all night), splitting responsibilities and cash...it's all really difficult. Make sure you go with a laid-back, open-minded group and you'll be fine.