Hey, stuff I can answer!
I went to BronyCon last year and plan to go this year (as I am their Head of Security, so I kind of have to be there). This year marks my tenth year working conventions (eleventh attending), and I tell you with all honesty that BronyCon June 2012 was one of the best conventions I have ever been to. It wasn't because of any event or panel in particular (though finding out that Lauren Faust's favorite episode is the same as mine was pretty cool), but just because of the energy in the air. Everyone there was so happy to meet other people and hang out and get excited about ponies. Last year, my internal drive was starting to stall, and the people at BronyCon re-ignited my passion for going to cons.
I flew, but I know a lot of people who drove, which is an awesome thing to do if you have a couple friends who are also going. (I'm a big fan of road trips.)
BronyCon this year is $70 for a three-day badge if you pre-reg, which is a little on the expensive side compared to other cons, but it's also going to be huge. (It's so big, we can fit last year's BronyCon into our main programming space. We're expecting 6-8000 people, and there is a ton of awesome planned - 2 nights of Bronypalooza featuring just about any fandom artist you care to name, the bigger-than-ever cosplay contest, video game tournaments, art classes, LARPing, an Artist's Alley that's half again the size of last year's, and a few guests that I'm personally really really excited about, like ***** **** and **** *****. And even with all that, the best thing about the con is just getting to make new friends and hang out with people you know you already have something in common with.) The main hotel for BronyCon (and the cheapest one in walking distance) is
the Hilton, which is $125/night. And this year, we don't have autograph vouchers or anything like that, so autographs are free. I do work for BronyCon, so I am pimping it just a little bit, but I also happen to like large conventions and I also think the price is genuinely worth it.
For J. Random Attendee who is going with two other friends, the cost of going to BronyCon is probably something like: $180/3 (for gas) + $420/3 (3 nights of hotel, with approximate tax) + $70 (three-day badge) = $270, which is less than I thought that number would come out to. (Then again, I'm flying and not splitting my room.) Don't forget to budget money for swag and food too.
I'm a bit of an old hand at conventions (geez, a full decade), so feel free to ask away if you have any questions.
-Rabbi