If the difference (for you) between the upgrade to the MegaPak and the UltraPak is $69... go for the UltraPak.
It will be THE best $69 you EVER spent. 500 RealTracks (mega) vs. 2900 RealTracks (ultra) is huge.
totally agree!
Although, if you do get the MegaPak and then decide on going the extra step within 30 days, past comments on these forums show that PG Music will refund the purchase of the MegaPak towards the UltraPak. Maybe this is something to ask sales staff about.