I put Saladfork's formulas into a Google Spreadsheet:
http://spreadsheets.google.com/ccc?k...qbxtQDTbO_z6SQ
Yellow Cells-- Put in your expected profit (ie, after AH tax) for various gems and enchanting materials.
Red Cells-- On the left, for Eternal Earth cost. Put in how much you buy it for (or opportunity cost of using, as it applies). On the right side, there's a red cell that shows the value of a single DE. Basically, since you'll have uncommon gems to use, it'll show the money you obtain if you use them to DE. You'll want to compare this value to the opportunity cost of using the gems (vs. vendoring/Auction Housing) + the cost of 2x crystallized earth.
Blue Cells-- Constant values derived from Wowhead. Change it if you want, but they seem accurate to me.
One thing though... can people who view this spreadsheet change the values? This is my first time using Google Docs. Do I need to change it somehow so people can update with their own server's values?
Edit: Should be fixed now so people can edit.
Edit2: So now it seems whenever anyone edits it, it shows up as edited for everyone. How do I make it so that it's just a public spreadsheet that anyone can change on their side only? Is this even possible?
Edit3: It's now set to private per adivce. Use File-> save copy to have a sheet you can manipulate for your self. Thanks Nagisamuro for the tip. Sorry for those who do not have a google account to save it to.
Also, continue to use at your own risk and check the forumlas-- people have been able to edit this sheet freely the whole day until I made it private. I take no responsibilities for mistakes until I get a chance to go over the sheet once I'm at home.