A 3-park (Seaworld/Busch/Aquatica) ticket on Seaworld's website is 109.95 (all ages)
A 3-park (IOA/Universal/W&W) ticket on Universal Studios website is 124.99 (all ages)
So its cheaper to buy them separate than to do the Orlando Flex ticket plus (299.95 adult, 279.95 kid)
Only downside is that the 3-park passes are only good for 7 days, so You would have to stagger when you used them if you had a two-week trip (do the Busch parks in week one and the U Studios parks week two)
Or is there a cheaper way to buy the Orlando flex ticket plus that I haven't found?