What a person may have paid for their kit may not always be the same. Dealers usually reward repeat business and loyalty with the best prices. Conversely, a poor attitude can negatively affect pricing. It happens in my business all the time, because I set the pricing at will according to market pressures. If I gave a loyal customer a discount, a freebie or otherwise special deal, it is common courtesy they not blab it to eveyone, much less post it on an internet forum.
A PM request like you said, would be a more appropriate way to get a response, IMHO. It's not "protection" but more likely a show of appreciation. When a person buys one of these, they generally plan on having it for a long while. Why not start out on the right foot and pick a dealer you can live with? It then starts a relationship which moves the whole "price" issue to one of value. Those who create value, in any market, will inevitably be the most successful.