Main thing is -- decide what you want to do. This is a beginner's server, so you need to decide what you want to learn with it. Do you want to learn the best possible setup for a big airline? Do you want to have a small regional one and find out what works best with that? Maybe a cargo company. So you want to determine that first... figure out what you want to learn and what's the best way to go about it. Now, for the discussion on what plane is best...
I'm not sure what good used aircraft will be if they are going to use the $10 million immediate delivery system. If that system is going to be used (and I'm pretty sure it will be), you are going to want to get new aircraft right away. Used aircraft will take an hour to get, and you might not win the auction. Someone might outbid you. The advantages of used aircraft are: they are sometimes cheaper, and they are available in one hour if no one outbids you. The immediate delivery program completely removes that... for the first $10 million.
Choosing what kind of plane, for me, is about the third or fourth thing to figure out when starting an airline. First is the hub. Second is the type of airline (worldwide, cargo, regional, continental, puddle-jumper). Third is the types of planes, and that choice really comes down to where the hub is at and the type of airline you'd want to fly. To make it simple... I'll just use the criteria I used for my main airline on Aspern. I chose Kansas City (MCI), because I love KC and all things KC, really. But the big advantages of it are: middle of the country, good local demand (7-bar demand), and within 2400 km from one coast to the other. Knowing these things, I decided to look and see what planes would benefit me the most.
To do this, I wanted to get a plane that would give me that range without losing passengers. I knew I'd be going less than the actual listed number of seats, so I could operate with planes that went as low as 80% weight capacity for 2500 km. That doesn't remove a whole lot from the list of planes. What I did was figure how many planes of each type I could get for $10 million, as well as what kind of general capacity they had. I checked the number of passengers available compared to the amount of money I'd have to spend on: security deposits, seats, and fuel. For my hub, the Embraer 195 was the best choice. However, that doesn't mean it's the right one for you. Here are some other things to keep in mind when you choose your type of plane:
* Keep in mind different planes travel at different speeds. This can make upgrading or downgrading routes difficult. It will be hard for me to go from a E95 to a 73G, which I'd like to do, but will be a tactical nightmare for me. Watch your speeds.
* Maintenance costs go up after the third category. In the beginning, used aircraft go fast, and there's a finite supply (usually). They aren't making 737-300s anymore, and unless the game world is designed differently, there will only be so many to go around. Once they're gone, you'll have to choose something else. It might be okay if you are getting old 737s, but if a dozen people start buying up all the MD-90s and -80s and the 717s, you might end up running out of planes you can actually get. Then, to expand, you'll have to get something else and add another maintenance category.
* Practice, practice, practice. It used to be that people would practice on the old servers. This is a new opportunity for many, many people to really start out practicing, hopefully without a lot of experienced people clogging up the system.
One last thing... and I hope I'm really wrong about this, but did anyone else notice the game world is coming out on April 1st? April Fool's Day? Didn't they have some kind of crazy space one they did a couple years ago on April 1st?