Yes, the current price of Maxwell is relativily expensive but I got it during its earlier pre-order development period (and suffered those terrible RC versions!). For people that make money from commercial renders then a good render engine soon pays for itself. whether it be Maxwell, Vray or whatever.

Render farms are useful for these sort of time consuming renders.

The latest render has been going many hours and is now at sample level 25. I stop it to do other things and when its feeding or TV time I resume the render (that feature of Maxwell is often overlooked and taken for granted)

Render time has no significance to me for this kind of test - I'm fascinated that a render engine can even do accurate spectral dispersion. However, the big problem with path tracers such as Maxwell is that they can't seem to cope with rendering the reflections of caustics (a reflection of the 'rainbow' colours should be present in the prism glass.

All this reminds me of the early 80's when computers struggled to do a decent ray traced image - the fascination never dies!