Switch Mode Alternative to LM7805/LM7905
There are specific converters for this purpose, named Split Rail Converters. These ICs consits of two converters in one package and have two output, +Vout, -Vout for each. Adventage is that the design will be much simpler and BOM size will be smaller too.

Example, TPS65133 :



This one is arround 2.6$. Note that this particular example could not supply as much current as you need, but I am sure that you can find a suitable one now. I just wanted to point out to search for one converter instead of two.