That is the rate we use for engineering hours. Sure as hell not what we pay engineers.
Seriously though, when getting into large projects considerable time and effort goes into cost evaluations. If I were to take the time to design something and make the board(s) that I can buy off the shelf for what becomes literally a few bucks they would fry my butt.
That is true, i suggest to buy it also and if it doesnt fit your need or requires to much alteration then consider a creating one. Time is one of the most important things you can waste. So try to save some and buy the item first.