Posted By:
Eric BI'm sure SGC and PSA have higher insurance premiums, but let's face it, in this market if you want top dollar at resale, you need to have a high end card graded. Therefore, they have you. Let me use this analogy..
I'm in the tire business. If you drive into my store in a 60K Corvette, you are going to pay between 1800 and 3000 for a set of tires installed. Now to most of us normal Joes, this would be outrageous for a set of tires. However, nothing to fix on a high end car is cheap. The line of thinking goes, "if you can afford the toy, you can afford to maintain it". Bottom line, tires for a Corvette cost this much, they just do. It is a way for the car companies to ensure they make some more money on the car after it leaves their lot.(whether it be parts or tires).
In a somewhat similar fashion, the grading companies(yes even SGC) figure, "hey if these guys have the disposable income to blow 7500+ on a baseball card that will probably appreciate anyway, they sure as heck can afford 100 measley bucks to get it graded." And to be honest, I guess I kinda feel that way too. This hobby is wonderful, but underneath it all, it's all about the bucks. I have a hard time paying 12.00 for grading, let alone 100 bucks, but then again, there aren't that many 7500+ cards in my collection. 
Eric