Rough or polished - which is your development? Chatting to an architect recently, he was frustrated with some of the CGIs another company had been created of his building.
"They just look nothing like they are supposed to!"
But, there was no budget for creating good images. Of course, we understand that budgets can be tight, so knowing where to spend is important.
The diamond on the left of this image (if it is actually a diamond - it could be a lump of glass for all I know, but that is partly my point) doesn't really look special, or valuable. When crafted and machined with care and skill, it can be transformed into the diamond on the right.
That takes time to do, and therefore there is an associated cost in that 'transformation'. But, sat in a jeweler's window, which would command most attention? Which is likely to be sold quickly, and with the highest price to the passerby?
I seriously doubt it would be the one on the left.
Good CGIs of your development are valuable. They make them easier to grab attention or excite people with, gain consent for or, ultimately, sell.
It is therefore worth the time (and, yes, the money) on getting them done well.