I've often wondered why Bitmain bother selling miners rather than just using them.
Bitmain sells its miners at a high price. The price Bitmain sells its miners for is the expected value of mining revenue, based on anticipated future growth in difficulty, and estimated costs associated with running the miner (electricity, and repairs), and the price of bitcoin, minus some discount rate to account for the possibility that difficulty will rise faster than anticipated, or that the price of bitcoin will be lower than anticipated.
So in essence, Bitmain is removing the risk of high difficulty growth from their balance sheet and allowing their customers to assume this risk. As Phil alluded to, this also happens to help them finance their manufacturing operation.
While it's possible that Bitmain does the kind of analysis and planning that you suggest, my bet is that they will essentially
charge whatever the market will bear. There are a variety of factors that fit into that, but competition usually matters as well. The semiconductor shortage has thrown a monkey wrench into every miner manufacturer's plans. We have seen Bitmain adjust pricing in response to competition in the past (e.g Spondoolies in particular).
BTC price and current trends in BTC uptake all factor into what folks are willing to pay. We have seen in the past a batch sell out in record time, and then the next batch is announced a few days later at a higher price. While I haven't paid close attention at an individual level, I don't expect that the practices of the past are ignored.