I wonder if the "Gigahertz per Hour" is good indicator anymore given the growing difference between CPU families. Westmere based X5xx are twice slower than more common E5 v1/2/3 now found.
When I compare your Ghz/H prices to Rebus, your cheapest is more than 200perc. cheaper (1.5 vs 3.3), but when comparing to actual render time equalized to same Cinebench score, the difference was only 20perc. (8 euro vs 10 euro for 10 hour render on 1000 C15 Cinebench points).
I know these are just estimates but it gets harder to compare prices now. But honestly, don't see much difference across all the competitors, expected more price under-cutting in 2016, I guess it's too good business :- )