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I just did my analysis on the market. It has usually always been 20%, it may be that there was an unfavorable price swing in the last check. However I should make another one within a couple of days

It's locked in at 21%, but based on the sell price instead of buy as your analysis, the difference between the two during must have been unfavorable.

EDIT: Another column in your table with the price you did your math on would be a great addition to your reports. Keep them up, I keep an eye on these for my own references.

Good idea. I will try to put the price in a new column!