We paid a lot of money to get a store template and auction listing template done. Had bulk revisions so we didn't have to revise each item individually. It definitely gives that professional look, especially if you have a website and get them both to look alike. However, sales wise, nothing has increased or decreased.
We find so many people look at the title, photo then variations and hit buy. 8/10 buyers I deal with have not scrolled down any further to read the item description. But then, maybe they are on a mobile device.
I know the above statement doesn't go for all, however I have dealt with two very different items. One where a product photo tells all, edit one to show the sizes etc and place that in there too. However, another item has a fully blown specification, what it's made of, whats inside it, how heavy it is etc. Something you cannot tell from a photo anyway.
It's something I would place some money aside over a period of time and eventually get one done purely for a more professional look. I would also save a few bob next time around and go for a template where I revise each product. Any new items listed will just be setup with a saved template.