Opinion: If anyone honestly believes that having 1,000 of the same image (or 100 or 20) with nothing more than filters or color shifts, is going to make them more money, let them be lost in that delusion. To answer directly, I don't think having the many will help or hurt anything much at all. I don't care, but I won't do that myself or just to have a bigger collection or more numbers. More images doesn't = more money.

I honestly think that any buyer who sees a page of, lets just be fair, 20 of the same image or setup, and was looking for something like that, they will find something else that stands out. You can't stand out in a crowd of similar looking images, identical images with nothing but color changes, or same elements arranged in minute variations. In the eyes of someone looking for an image that stands out, for their use or illustration, you have just made your work look like something, common, ordinary and the impression is they are not special or unusual in any way.

Why would any of us intentionally make our images look common, or ordinary? Seems like our goal is the opposite, in order to attract buyers.

If there's a reason or an angle or some change, in a similar shot, that would justify any different versions of a similar subject, by all means do that. I won't say, don't do many of a subject just based on numbers, just because of the number.

Just like keywords, only as many as are needed to properly cover the contents for a search, only as many images to cover the concept and creation of the composition.

What anyone else does, is of little concern to me, I'm just expressing my personal view of what I do and what I upload. I think that's a better plan. I might be wrong.

Did I ever say this before? Less is More? 

In my view its a sure sign of a poor photographer/image producer to shoot angle variations and then put them up for sale.

Its best to keep the best shots and delete the rest.