It's not only the "Big Box Stores" that are putting the small shops out of business, but the "Online Retailers" like Amazon that sell filters for $39 when the cheapest locally are $59!!!
Yea those online guys are horrible.

You need to look at online retailers in a different light. Those retailers are not the problem, but of course I would never admit that I was part of the problem.

They are the effect of the problem not the cause of the problem. The problem is the manufacturers that choose to do business in the manner that they do. Manufacturers sell their products based on volume - buy more units and the price goes down. That is the way the world has worked for basically ever. The problem comes into play when a retailer can order more than most distributors.
Those retailers can than sell their products to the public for less than the typical distributor can sell them to stores. This creates a situation where a manufacturers products have no price integrity. The sad thing is ALMOST ALL manufacturers don't care. They are run by people just worried about keeping their jobs by getting sales by any means necessary.
The only thing of real concern would be how Amazon operates. Few people know that it took Amazon 8 years to show its first profit. The reason is they wanted sales at any cost - even if it meant a loss. Any independent book store that didn't drastically change its business model went under, followed by the big box stores. They didn't worry about making money, only taking as much volume as possible and in turn putting everyone else out of business. Now that they are the only one in the game of books, publishers have to play by Amazon's rules and Amazon is making profits. Amazon's agenda is to do the same thing in EVERY product category - including pets. I don't like what Amazon is doing, but to be frank it is pretty impressive at the same time. You as a consumer should be concerned for 2 reasons - 1) if independent pet stores continue to go out of business that will severely limit availability of live stock and 2) once all the Amazon's competitors go out of business prices will sky rocket on Amazon.
And to those who think that Amazon won't ever put everyone out of business - I'm sure that is exactly want Borders and Barnes and Noble thought 5 years ago. Now I don't even know where there is a book store. I hope the same things do not actually happen with in the pet industry.
My advise to any retailer of any product line: be proactive and start supporting those manufacturers who don't whore out their products. If the public can buy something from a competitor for less or the same price you can buy it for then don't sell that product and replace that product shelf space with something else.