For the 9th through 12th I see a rate of $294 at Royal Pacific. More than what you originally saw, but...
I like using
this site to check the Universal onsite hotels all at once. It allows me to see it all. And I can put APH into the Code box, to see if there's an AP rate at that time, for that time.
Rates can change around. April, of course, is going to be an expensive time, and if, for instance, that Royal Pacific rate is acceptable to you, I'd book it now. You can change it later if another rate comes out, even an AP rate (if you do the math for upgrading someone to an AP and the total makes sense, of course).
Doing Disney first is good because then you get the really good Express Pass at the end of your trip, and you can revel in how sad the Fast Pass concept is, LOL. But if you have a really nice room at Disney, like at DVC, where you have lots and lots of room, then doing Disney at the beginning can make the Loews rooms look really REALLY tiny.
Depends on what's the most important to any given family!