There is one price you can sell Bitcoin at: the market price.

There are two prices you can buy Bitcoin at: the market price and the mining price.

In bull markets, the market price of Bitcoin is well above the mining price. This incentivizes those holding Bitcoin to sell, and buy mining equipment. This is relatively common.

At this moment, you can buy Bitcoin on the market for well below what it costs you to mine Bitcoin. This is relatively uncommon.