Cary - to clarify your partially-correct comments:
SePRO markets their 1-gal. and 40-lb/30-lb pails of SONAR AS & SONAR Q/PR/SRP (respectively) under an "agency" arrangement - where pricing is generally "set" by the mfgr when products are purchased from a designated "agent" within a defined territory. However, pints, quarts and 8# pails of SONAR are not included under the same arrangement and are sold at open-market pricing.

I don't know what qualifies as a "big chemical warehouse" company to you, but Estes Inc operates in 5 states, with 18+ warehouses and well over $150MM in annual sales. We are the only SONAR agent in TX, OK and NM - but also service AR and LA as a SePRO-designated agent.

Our primary customer-base consists of dealers, commercial application companies and government entities. We're generally not staffed, promoted and "store-fronted" to service the retail/end-user market in the same manner as our valued dealer and custom-applicator customers. Therefore, we do our best to support these important links in an efficient and value-added distribution-chain (meaning that I would encourage small pond-owners to place higher values on provided services and advice, rather than focusing on saving a few bucks by seeking the absolute cheapest price from any business that cannot offer intelligent & experienced advice).

I enjoy contributing to this board, since the subjects and info-exchange are of personal interest to me. I certainly don't invest my time here from a commercial standpoint (unlike a few others).

Bottom-line: Few people shop around for the cheapest doctor, since they usually want the best healthcare advice available - assuming the price is affordable (in this case, how do you define "affordable"?).
If I was a pond-owner, with a relatively large investment in my pond's construction and fish-population management, I would seek my pond-supply OR service-provider based on similar selection-criteria (ie. experience, qualifications and willingness to assist with problems) - and not based on the cheapest price.
See some wise words of wisdom below.

WHAT IS YOUR "BEST PRICE"?

It is unwise to pay too much, but it's much worse to pay too little.

When you pay too much, you usually lose only a little money - that's all.

When you pay too little, you sometimes lose everything, because the product or service that you bought was incapable of providing the desired result for which it was purchased.

The common law of business-balance prohibits paying a little and getting a lot; it can't be done!

If you deal with the lowest bidder or the cheapest product, it is often necessary to budget a little extra expense for the risk that you take in order "to save a little money", and if you do that you will have enough to pay for something better that works the first time.

Kelly Duffie
Cypress, TX