If memory serves me right, about the best price you'll find for the Remora Pro with the better Mag drive pump is about $225, and will be found at Marine Depot and many of the sponsors of this forum for about that price. You can also find them used here:.
Reef Central Used Equipment Forum
Of course, it's a bit of buyer beware when buying anything used, especially from someone at a distance, but I've been fortunate, and haven't been burned to badly in the many purchases I've made. Asklots of questions, and check to see if there is any feed back (good or bad) on the seller. Also try e-bay for one.
No experience with the sea clone. Too many people warned me away from it when I got back in the hobby.