Here's an article I collected on soil mixes. You may also want to check out this link.
http://forums2.gardenweb.com/forums/...580016564.html
I'm using Myco Madness for my container plants.
http://www.plantlightinghydroponics....oz-p-2638.html
I agree that shipping costs can be high for online stores but I find the store above has reasonable prices, especially if I order multiple items, and quick delivery.
I also bought 4 cubic foot bags of coarse vermiculite and perlite from a local garden store. They carried the brand shown below. I sifted the perlite using the pond basket below to remove the sand-size particles.
http://www.greenhousemegastore.com/p.../seed-starting
http://www.greenhousemegastore.com/p...-soil-handling
http://www.homedepot.com/p/Beckett-1...0#.UiVbjz9czwI
If you have a Lowes nearby you can use this for pine bark fines.
http://www.lowes.com/pd_97675-66882-...ner&facetInfo=
http://www.lowes.com/ProductDisplay?...llow&cId=PDIO1