Tested in Brave on macOS, English, Generalist, with the guide on, in a window about 1000 pixels wide. I stopped on reaching port 2.
The first sale worked. I bought Diplomat's wig for 3 credits, matched Ancient to Lord Archivus, and saw 8 compared with 4 from the other buyers. Personal story raised the offer to 14. The service fee of 1 left 68 credits, then the flight cost of 8 left 60. Seeing the buyer, action and fee together on the sale button made the cost clear.
One readability suggestion for step 13: the Next port button is highlighted, but the departure cost line stays dimmed under the tutorial overlay. Putting the fare on the highlighted button, or including that cost line in the highlight, would make the final decision easier to read.
At port 2, the tag matching gave me a clear next step, compare cargo with the new buyers while keeping the 10 credit departure reserve.