Last time I sent cca 1 BTC to my father's account the original Bitcoin client I use (version 0.8.5) required me to pay 0.0015 BTC fee. Now, BTC is reaching $1000 in China, making this fee 1.5 USD. That is not a small fee. I think we can't say it is unrealistic to work with scenarios of BTC being valued $10000. Would fees be extreme by then? Or is there a possibility (using the original Bitcoin client) to really pay something like 0.05 USD that I find a reasonable fee for "small" transactions such as 1 BTC? How about 0.1 BTC transactions or even smaller transactions? Thanks for explanations.
The current recommended fee is 0.0001 BTC per kilobyte. Unless you've received a significant number of useless expensive dust outputs, the typical transaction is less than 2 kilobytes. As such, your fee should be less than 0.0002 BTC (at $1000 per bitcoins that's $0.20). In the past as the exchange rate has soared, the recommended fee has been reduced. I think this has happened 3 or 4 times already. If the exchange rate gets to be significantly above $1000, I'd expect that the recommended fee will be reduced again.