a) I wanted to pay LJ back for all the awesomeness that is LJ. Like the ability to keep in touch with all of you amazing people!!!! Don'tcha think that's worth $150? I do. :-P
b) I'd rather pay the lump sum of $150 than pay monthly or yearly and get less features... *shrug* That's just me... always lookin' for a bargain.
$150 = 6 years (pay by year)
$150 = 5 years (pay by 6 months/2 months)
And in a very pathetic way, I feel like I'll still be lj-ing in 2011 (which is, btw, the year my brother will graduate from high school).
c) I'm rather insane. :-P