It's nearly double the cost for a lift with flex arms ($1,500 vs $3000). Are they really necessary (sorry I'm a n00b)?

 

What height are you going? I have the Tera 3" (gave me over 4") and I got the half set of flex arms and adj. track arms. The jeep drives better now than it did with only 2" BB. The xtra caster and having all the geometry correct really makes a big difference. When I can aford it I will change the other 4 arms. Plus those tera flex arms are really well engineered and overbuilt. I think they are worth every penny.

 

Going 37" tires.

Unless I can get 38"s

 

then spend the money and do it right. otherwise you will regret it... or worse spend the rest of the time you have your jeep trying to make it drive like it should. Get the arms, and get the geometry back to stock and you will love the way it drives. I haven't seen anyone say they wished they had not got them and they were a waste of money.