I believe SoCalMama's point is that the going rate for experienced hotel shoppers is $200 to $300 per night. Assignments are generally 2 nights, hence $500-$600 is the rate. This is in addition to all expenses (airfare, ground transportation, all meals - including a per diem to eat off site on travel days and/or if the hotel is smaller and it doesn't make sense that all meals be taken at the hotel or resort).
Does this mean that everyone that gets this rate always gets this rate? No, not at all - I will often take a hotel at a lower rate than this because there are other benefits in it for me (I want the points, I need a hotel room in a particular city, I want a weekend trip for my best friend and she loves the hotel, etc.) She isn't going to tell you the names of the companies (and there are many, it isn't just one special company that pays far and above what everyone else pays - in fact I can guarantee that the majority of the companies most of you are already working for) - because even if she did, it wouldn't matter. They aren't going to just hand you a trip to Bali all expenses paid and a fee of $300 a night because you wrote to them and asked. Its about paying your dues, finding the project that works for you, networking and most of all paying your dues. My advice, which I give to everyone - via PM or on the forum - is just keep doing what you all are doing, doing it well, showing grace in what you do, a strong work ethic, good communication, be kind, and never ever dismiss a company or a person out of turn as "beneath you" or not worth your time. Kindness, respect, and class go a long way in business. This is no different.