The PADI ReActivate is about AU$100. So I reckon you could potentially pay about the same in US$.
Since I think the entire ReActivate is just another way to get money out of divers, the way we usually do it here, is we take you on a normal dive, sit you down in the beginning of the dive in shallow water and do a number of basic skills from the Open Water course with you. If you show you can do these without any issues, we'll continue with the rest of the fun dive, and you pay for just the fun dive.
If not, THEN we will continue with the entire Tune Up, which would then of course cost a bit extra.
US$750? Total rip off.
US$150 for educational material? Still total rip off. The cost price for an Open Water manual + certifying credit is appr. US$75, the entire course hovers between US$300 and US$450 depending on location.
This guy...
I guess business men are free to decide their own profit mark-up, so I can't really call him a thief. But... well... What do I know, anyway...
I'm sure "everything is better with SSI", as he so many times has said.