I wouldn't charge different rates. The way I look at it, when I'm charging an hourly rate, the client is paying for my time. What value the client derives from

I wouldn't charge different rates. The way I look at it, when I'm charging an hourly rate, the client is paying for my time. What value the client derives from that time isn't really relevant to the cost. Or put another way. I know I can sell my time at X in the market, because I have done so before. Thus, it makes no sense for me to sell it at a rate lower than X, regardless of what I actually do.