(a lot of what is below is pasted from previous BotCon topics, so there might be some duplication... and very lengthy, sorry)
You can pre-register if you want to be able to do "everything" (Wed-Sun) and have the money for it, OR, pay on the day for single-day access which is cheaper but limited to ONLY Saturday and Sunday DAYTIME events.
Pre-registration is something that can be up at any time, as they don't have a set (or even rough) schedule, but most years it has been 3 months before the start of the Convention (best has been just under 4 months, worst has been 1 month). So if this year is like the most common, it would be the end of March.
In regards to pre-booking things in advance...
Most of the main costs will be paid over a period of time so that it doesn't all hit at once.
5-6 months out - book hotel (as soon as it is announced) - if you are definitely going you could consider a pre-paid hotel to get the cost out of the way, otherwise most hotels will charge one night at booking, which is some of the cost covered.
3-5 months out - Airfares & Insurance - as early as you can, usually helps get cheaper fares. (and passport if you don't already have one)
2-3 months out - register (as soon as it is open) & Club Membership if you don't have it (for the BotCon discount).
0-3 months out - book and pre-pay other activities you want to do while over in America, and use this time to save up trip spending money.
0 months - spending on your trip and Convention, then .
After - Accommodation paid on check-out... and any credit card interest if you went a bit too crazy on the trip.
Approximate amounts of the main costs (AU$)
- Return Airfares to America (Los Angeles), $1000-$1500 (sale fare), $2000-$2500 (full Economy).
- Return Airfares within America if not in LA, $300-600 (depending on your package deal with your airline)
- Travel Insurance, $100 (MUST GET TRAVEL INSURANCE WHEN TRAVELLING OVERSEAS)
- Pre-registration, $500-800 (depending on how many add-ons you include)
- Club Membership, $82 (MUST JOIN THE CLUB BEFORE REGISTERING TO BOTCON - it will save you $85, which ends up getting you a free toy & magazines)
- Accommodation, $150-200 per night (if not sharing, and are staying at one of the Botcon hotels)
- At-show toys & merchandise, $300 if buying all 7 toys and t-shirt.
- Additional spending would then include toys, food, transport and entertainment. (give yourself about $50 per day outside the Convention, and then whatever you want to spend in the Dealer Room)
NOTE - sales tax is always extra in America, and in California can be about 8% on purchases, and about 15% on hotels.
*Airfares should be planned out with a Travel Agent as early as possible, and if the seats aren't running out, see if you can wait a couple weeks to see if a sale pops up (if there isn't already a sale on at that time).
*Pre-registration should be booked and paid as soon as it is released by the organisers, as some components can sell out within hours or days.
*Accommodation should be booked straight away (details are on the BotCon website above). NOTE that the Hotel might ask for a deposit now, to screen out all those people that book early but never go, leaving a lot of empty rooms that attendees missed out on (and had to book elsewhere). Check the fine-print to see if the Deposit is refundable if you cancel before a set date. If you do end up going, the rest of your stay is paid when you check-out (but they will usually put a hold on the estimated amount when you check-in).
*MAKE SURE YOUR PASSPORT & VISA WAIVER is valid, with enough time left on them to cover your trip. Go to a Post Office at least a month or two before you leave if you need a Passport, and go to this US Government site if you need a Visa Waiver (it is then valid for 2 years, so keep the details recorded somewhere in case you go back to America within that time). Cost for the Waiver is about US$14. (it was free before Obama became President, raising taxes)
*Plan out your time over there, with some backup plans in case something doesn't work out. Maybe print up some maps to help familiarise yourself with all the places you plan to go (look up their addresses), and where you are staying. Have at least 2 or 3 different money sources to utilise (cash, keycard, credit card, pre-paid cash card, etc), and have contact details with someone who can help you out if you need help (either someone else there, or someone back home that is easy to reach and can send you money if needed).
*Be mindful of any differences in the Laws over there. There wouldn't be anything significant if you are over 21.
*BE AWARE OF TIPPING while in America. A lot of "service" jobs over there require payment of a tip on top of what ever you are buying, as it is part of their wage to survive on. There are different tipping rates (at least 10-15% of the bill, or double the tax amount are two examples), but it is up to you as to how much you give, if at all.
*Have fun and don't stress too much about what could go wrong. If you have Travel Insurance, and your airfares were paid way back when you booked them, you only have to worry about getting back to the airport, to get home.
A recommended list of things to pack on a long-distance trip.
Recommended mapping out of your travel plans.
Previous years meets (for an idea how these things are planned and play out)
2014 and here
2013
2012
2011 details
2010 details
2009 details
BotCon Reports of mine (what to expect there)
2007 - Rhode Island Convention Center, Providence, Rhode Island -- June 29 - July 1
2008 - Duke Energy Center, Cincinnati, Ohio -- April 25-27
2009 - Pasadena Conference Center, Pasadena, California -- May 29-31
2010 - Disneyworld Dolphin Resort, Lake Buena Vista, Florida -- June 25-27
2011 - Pasadena Conference Center, Pasadena, California -- June 3-5
2012 - Hyatt Regency, Dallas, Texas -- April 27-29
2013 - Town & Country Resort & Convention Center, San Diego, California -- June 28-30
2014 - Pasadena Conference Center, Pasadena, California -- June 19-22
(or go here for an index of the various events over the years)
There's a lot of reading in all that, but it's a big trip... so either go blind and run off adrenaline (like I did for my first one in 1999), or plan out everything with backup alternatives to limit problems and surprises (like I do now).