Lownote,
The answer to your questions is "Yes". While most places will charge the same price as what you see online, the difference is in the shipping. The dealers are the same dealers as you see online, with the big exception of Nicholas Smith. For whatever reason, he has a huge inventory of late model Aristo equipment. Older black and gray box stuff. Be advised, Friday is typically a 'feeding frenzy' at this show. However, toward the end of the show on Saturday is when you can make some good deals, so there's reason to spend the weekend at the show. The dealers include St Aubins and USA Trains (Charles Ro), Trainworld, Start Hobby, the list goes on and on. You can find all the details of the dealers, at the Aristocraft board. However, there are a lot of the smaller manufacturers that you might never hear about, like Colorado Models.
I have been going to the ECLSTS since 2002, and with each year, I feel it gets better. Even though I like to buy train stuff when I am there, I really like meeting up with my large scale buddies, many of whom I only see at the show. Be advised: this is not something you'll want to schedule an hour or two for. It is really an all day event, two really. My wife will come for an hour or two, but I can spend the entire day there. Browsing dealers, chatting with friends, making new friends, browsing the dealers again, hitting the ATM, viewing operating layouts, etc...
You will be able to find everything and anything made in large scale. Plus, you get to hold it in your hot little hand before making the purchase. Also, you will find deals that you cannot find online. Example, USA trains streamlined passenger cars: 5 car set is typically over $1000. At the show last year, they were selling for $900. They had a bonus deal for an extra $200 you would get a PA PB. I don't remember why, but when a buddy bought the 5 car set, but didn't care for PA's, I didn't try and buy the PA-PB. Oh! That's right. I bought sound.
Anyway, it is a really great event, and it is about as much about getting great deals as it is about making friends and sharing the hobby.
Mark