1) I don't value or appraise logs via this forum; calculate the board footage of your log and use your state's timber price reports to estimate a low, average, and high price estimate based on the "quality" of your log.
PA Timber Market Report:
http://extension.psu.edu/natural-resources/forests/timber-market-report
2) I'm going to assume the diameter measurement you provided me is DIB (Diameter Inside Bark; small end of log). My estimate will obviously be off if that is not the case.
International ΒΌ Log Rule (18" DIB x 14' Length)
Board Feet = 200 board feet