If you feel as though these assets are not worth the asking price, you are entitled to not purchase them. If you feel you can do a better job, then by all means, the marketplace would benefit from healthy competition. To gripe and moan about current prices of assets devalues and insults the artists/developers. You can vote with your wallet here, just like any other market.
I will see that pricing more reasonably appears to be beneficial from a consumers stand point, but as an artist, I’ve found that charging more for my time and my work typically yields better results. I am not competing with the bargain bin, and I can provide fuller services to fewer clients, while maintaining a consistent income. There are both pros and cons to pricing your content, and the fact of the matter is, its up to the artist, and what they feel is reasonable for their time. You can provide your opinion without being inflammatory, or disrespectful.
In addition to that, provides a pretty kickass service, and hope that you continue to get business, as all of your assets I’ve seen have been pretty **** solid, especially for the price.