Yes your are right and no your are not right.

I would need a list of all batches of S9 with price and power consumption.
S9-Batch1
S9-Batch2
And best would be to put every batch with different Specs and/or price inside this table as a new product.
But for myself: I decided to take an average

Some like S9 and Whatsminer are giving a range of Hashrate (13,5 to 14,5 / 11,5 to 12,5) and they say: +/- 10%
And therefor the batches had different prices ranging from 1400 to 2000 USD.
I think and feel that sometimes even the same batch (production) got different prices and they raised the price during sellings.

For S9 I took one batch I did bought myself at this price some weeks ago (ok ok, 3 month ago).
For Avalon and S9 I took the average I know myself.
For T16 I took the data of the video.
For Ebang and the others I just took the specs from the site.

A higher price would lead to more price / each Th/s for Bitmain.
Always after the red BUY button of Bitmain is out again - I put in the new data to compare