Well not really, not at nearly $1k each

I feel like the two should be enough since I’m not really into SPS, but going with three would definitely mean not having to worry about future growth, as
@Rostato and
@saf1 point out. I just want to decide now, since I intend to ceiling mount them and don't want to have to patch holes above the tank.
I had two AP700s over the 525, which was 2’ shorter, but I only ran them at 45% power. Those supposedly had roughly the same coverage (48” x 24” at 18” above the water), so I feel like two would be fine if I just up the power? I do want them mounted fairly high, though, so that they aren't in the way when working in the tank. I figure that any SPS would just get mounted at the top of the rockwork, but I mostly like softies and LPS. I was planning on a nem of some kind for the clown harem, though; either a carpet or an LTA, which would probably both be at the bottom of the tank. Hmm.
I’ll have to see if
@OZ_SPS will let me borrow the par meter when the tank is actually in place.