I'm not sure that home depot sells the laminated? particle board used in ikea furniture. If you used unlaminated particle board, you'd certainly come out a lot cheaper at home depot. heck, most ikea desks could be made out of one 4x8 sheet, so even if you used slightly higher quality plywood, you'd probably come out ahead in terms of materials cost.

Yup, for less than USD$8 you get a 4x8 sheet of OSB[1]; I'd bet money that stuff is stronger than the stuff ikea makes desks out of. Now, I dono how much it takes to laminate that stuff nicely like ikea does, but the raw materials for cheap 'engineered wood products' are incredibly inexpensive. Heck, for $2 you can get an 8' long 2x4 that is actual wood. buy two of those and you can build something much stronger than the standard ikea desk.

Now, I'm sure it costs ikea less to build the desk than it would cost you to buy the materials, but just like amazon isn't going to sell you compute nodes for less than the cost of buying and co-locating servers even though it costs them less, ikea isn't going to sell to you at those prices.

[1]http://www.homedepot.com/Lumber-Composites-Plywood-Sheathing...