I think the most fair way is something like 2-5% across the board with no minimum limit. This way, the small fries can still take out their money. God forbid people with a lot of cash actually give some of it up (to make it worthwhile for TradeHill).
Originally, I proposed and it was decided for a long time, we were going to have a % rate, like what you said above.
The issue that was raised (I will not name names) was that there may be hundreds of <$50 amounts where the profit would only be a few cents.
For the parties involved, this was unacceptable, thus the current fee structure came to be.
Trust me, Im pissed as well. If you look at one of my earlier posts, I even wanted to do this for free! Even now, we're barely making a profit off this.
Why do you think MtGox decided to cover part of the fee? They know that most of the customers will go to them anyways, but we're all doing this for the good of Bitcoin.
But the thing is this shouldn't be an opportunity for profit. It's great that BitInstant wants to help and same with Gox, but TradeHill should take absolutely 100% of the fallout from this. It doesn't matter that hundreds of accounts are less than $50. Their business model failed, and they should suck it up and eat their losses. It's a gamble. If I make a mistake with my money and my investments, I don't ask the Bitcoin community to cover my losses.
"For the parties involved" fails to include the consumer, and it's apparent that the current decision is unacceptable to at least some of us. This isn't your money, or TradeHill's -- it's our money (property) and it should be us who has the largest influence over this decision. I've never done business with Gox because of many bad decisions that they've made regarding customer service (mostly a lack of it, and I'm guessing the lack of customer service is there because they simply don't want to hire more people to specifically handle customer service issues).
Starting a business, especially a Bitcoin business, is an extremely risky endeavor, and it should come as no surprise that many Bitcoin businesses will end up failing and losing a lot of money. That is the risk they took. I view this as stealing, even with the 2-5% fee structure I suggested. But, at least that's me trying to be nice and offer a compromise.