Hmmm... As much as I hate to say it, I'd fix the arbitrage opportunity. Make magic arrows sell for less than what you buy them for (perhaps an even trade with the Merchant trait). That would make the game far more challenging, I think. At least for me, it would
Of course, half the time in the game is spent waiting for the delay after NPCs speak. Having the ability to hit space bar to step through would be very helpful...
Nice question, Wyv!