Having a friend recruit you is good, but it's not the be-all-end-all. I have lots of friends on other teams, and we might beat the snot out of each other on the singletrack and then laugh about it over beers later. Ain't no thing.
I think the team's personality has the most sway for me. Do people just show up to the race and then leave straight after, or do they bring their families and lawn chairs, grills, and coolers? Would you be expected to do all the races in a series, or do volunteer work, or pay a membership fee? Can you get coaching, are there group rides outside of races, and is there a mix of hammerheads and caboose riders?
I started with an all-women team that did road and mountain, lots of focus on beginners, tons of group rides, but little true racing. I eventually switched to a rowdier co-ed team that brought kegs of beer and cheered/heckled absolutely everyone on the course. Each was the right thing for me at the time.
Oh, and as for the team deals, I believe the statement still holds: get the best you can personally afford. What changes is that what you can get for the same amount of money goes up.
-- gnat!
Windsor: 2010 S-Works Ruby
Pantysgawn: 2011 S-Works Stumpjumper 29er
Whiz!: 2013 S-Works Crux (Singlespeed)
Boucheron: 2009 S-Works Tricross
Haloumi: 2013 Tern P7i
Kraft: 2009 Singlecross
Gouda: 2005 Electra Betty
Roquefort: 1974 Stella SX-73