Yeah, their high season ends April 15th. But if you look at the bill they send you, you're getting both parts (high and low season). Their high season rate is over $90. That's why I scheduled for the 16th (I was leaning towards going there til I found a $69/night deal at Coco La Palm).
After checking trivago, that $83/night (after taxes) is still a deal on the beach for that time frame. If you can push it to after the 15th, you can find alot of deals on the beach (including WS).