Everything about the Batmobile in this post is an assumption:
1. Why do people keep saying the Batmobile is too short? It may "look" short from the photos, but without measurements, its impossible to be certain at this point for this piece.
2. The shade and gloss level of the finish looks fine to me. But the thing about this Batmobile, as it appeared in 1989 (before the jet-black high-shine Returns version) is that it's finish is very subjective. Different photos and screenshots of the actual car seem to contradict each other based on the lighting or shine level bouncing off of it in different scenes or shots. In some it looks almost black, in some it even looks almost silver and anywhere in between. And then on top of all that, you've got to consider how the actual movie prop is colored (how it would look in a well lit room) versus how it was meant to look...how it looks in the low-light night scenes of the movie. It's a very difficult thing to pin down, and since there is so much variation in appearance for the same car, I think Hot Toys did a pretty good estimate...even if this is not the final color.
3. "It's overpriced." We simply don't know this for a fact yet. All that's been going on is a lot of speculation based on an unsourced message board post.
To scale, the Batmobile should be over 3 feet 7/12 inches long. I guarantee you that it isn't that long, therefore it is short from that standpoint. Proportionally, it looks like it is too short compared to it's width. If you are fairly adept at eyeballing things, you can tell this. As an artist, I need to be able to gert proportions right, so I am quicker than most people at eyeballing proportions, and as there are other artists here, they can do the same. The reason it is too small is to so it isn't too big for most people's collections. A correctly sized one would eliminate about 70% of potential buyers. It is also smaller to lower cost.
The original movie car was a pearl silverish color, as sourced from Terry Ackland Snow, who built it. All colors look different in different lights, and so the darker the lighting, the blacker the 89 Batmobile gets.
I don't really know whether the car was supposed to look black or not, but most people expect it to be. The real pearl color of the car would become obvious in broad daylight, and so if some people saw it then, they would believe that the car was painted a different color than it was in the movie, because they could never really tell what color it was in the film, and simply assumed that it was black. (They assume this even though you could easily see the contours of the car much easier at night than you could ever see, if the car was REALLY painted black. A lot of people don't think about this, and still assume that it was black.)
This color is as close to the real color of the car as red is similar to orange. If you wanted to film a red Ferrari at night and wanted it to look red on film, you couldn't paint it red, you would have to paint it red orange, or orange instead, because at night, red looks like dark maroon. What color would the car be, REALLY? Is it specially painted orange car used in the movie, or is it just the regular Ferrari red, Rosso Corsa painted Ferrari? It is a matter of opinion.