Mining costs aren't something to be ignored.Putting a valuation on a crypto asset like Bitcoin (BTC +0.50%) is harder than it sounds. Traditional valuation methods intended for valuing stocks or other assets simply aren't very useful, as the coin has no cash flows or balance sheet.But there are a few creative ways to figure out if Bitcoin is overpriced or underpriced that don't rely on a gut feeling or a biased impression of recent price action. In fact, one of those valuation methods suggests that Bitcoin ...