For reference leowaste sell a silk touchI unbreakingIII for 8k Mine also has EfficiencyV. This is the best pick you can enchant ill go to 12k
i'll go to 7.5k Edit: The reason it went to 8k was because back in the old days they were worth a lot, now, theirs soo many their not worth as much.
actually, eff brings down the price of picks. It ruins the picks faster. (want to mine one block, mine 5 of them behind it)