...we don't have a database of all past time exchanges prices
I really don't think there's a single exchange out there right now that DOESN'T provide historical data about their past exchange rates. mtgox's data is quite nice. covers all of their rates for multiple currencies going back to when << some currency >> was first traded on their exchange.
Really agree that this feature could be convenient for other purposes than the one you listed.
...First of all, it's going to be a little while. I need a new wallet format. Read a few messages back in this thread for more info.
Second of all, why is this such a dealbreaker for folks? I'm not looking down on anyone for this, I just don't understand why this feature is so critical -- in fact, it's going to cause so many problems for people I don't even want to do it. Bitcoin-Qt is especially not suited for multiple programs using the same addresses at the same time -- users will end up with locked coins and incorrect balances and it's really difficult to fix.
So if I wanted to delete my wallet / history / addresses completely out of the mainstream satoshi client (bitcoind ... or bitcoin-qt if I was using the gui version. apparently they both use the same wallet & blockchain data)
Expecting this to work... maybe the dealbreaker isn't that it currently doesn't work... Web browsers can import history when you install a competing browser. email clietns too, etc.
Why should I have to:
1) cause extra wasteful traffic in the blockstream to send money to myself as a workaround
2) pay any related transaction fees for something that shouldn't require network traffic
3) justify wanting to use a (currently broken) feature that has a button right inside armory in a conspicuous place
My dealbreaker isn't wanting a feature to work. It's that project lead / main dev has a half-arsed feature that doesn't work...
What's with wanting to shift blame to people who have a use for the feature rather than fix the current state of incompatibility.