It all depends on what the potential buyer may need.
If he for example is doing a short animation (need this attribute for some reason) and uses Pixar renderman then it would need to be a good sub-d cage. Those kind of render infrastructures usually perform global sub-d at rendertime.
There is actually no way to predict what one needs, there are many render systems, many different people whit many different workflows. (not everyone needs a good sub-d cage)
From my point of view everything looks aright with your model (as a regular polygonal model). Maybe the round edges (overhaul contour) could use some extra subdivision, however I see some potential problem to subdivide this model. Some smoothing problems may arise due to transition of low to high poly's in the center.
You used allot of poly's to form the center circle opening, if this would be a good sub-d cage, 8 to 12 poly's to make a circle would be enough. The small detail rosette could be a separate element within the cage having more poly's.
Also more renders and close ups would be a nice.
