In the crafting windows would it be possible to add a profit column?

Unless I completely misunderstand your request, this feature has been a part of Skillet for years. Skillet has a collection of plugins for various Auction House addons to provide cost information. The display of this information is controlled by Skillet Plugin options. You can enable as many plugins as you wish and they display on the details side of the frame. You can pick one plugin to display on the recipe side of the frame.

Skillet has extra support for the addon Auctionator so that's the one I use. The options for Auctionator are shown below (I normally add "only Positive") and the results are also shown below.

Note: Some of the plugins are for addons that are no longer actively maintained. Most plugins check for the existence of the addon and will exit cleanly. If not, don't enable them.

If this isn't what you are asking for, then let me know here.

Note: The AH cost of materials (and the cost of finished goods) rely on the AH addons ability to collect this data. For Auctionator (and Auctioneer), this information is collected by scanning the AH. Skillet also relies on other addons and/or merchant scans to determine if items are buyable or not. In the example shown above, I believe Penumbra Thread is a buyable item, but my character has not visited a merchant that sells it and someone is scalping in the AH.