I've never seen any advantage in using a pre-made mix. It can be a bit of a search finding the raw materials in large enough quantities to mix my own, but I enjoy finding new sources.
Peat moss - 40% Coir (inoculated version) 30% Perlite - 10% Vermiculite - 10% Pumice - 10% Dolomite lime to balance the peat moss deal (sometimes I use oyster shell flour just to relieve psychic boredom) Yucca extract as a wetting agent Then begin figuring in the organic material and soil amendments. About $5.00 per 1 cf. which includes all of the above plus compost, earthworm castings, seed meals, fish bone meal, Canadian glacial rock dust, kelp meal and dis and dat. All I need now are some really killer graphics and I could go into the soil business! Not.........
Mine is basically the same except i subtract the coir and add it to the peat--or sometimes sub some compost--and I subtract the pumice and add to the perlite/vermiculite. This year I'm going even simpler with just perlite and peat plus humus and other nutrient additives.
Where to get air pots: http://aroidiaresearch.org/airpots/ $7.75/5gal. The shipping is a bit steep though. they are out of Flordia. I think I am going with the smart pot, even though these would be a lot easier to move around. I believe either of these would be really good for a healthy root system - more 02 and CO2 for them. Good luck on the season!!
Instructional VIDEO re how to make your own Air Pot. About 7-8 gallons or 1+ cubic foot of potting mix/soil: CHEAP & EASY DIY AIR POTS. I made 8 of these Dollar Store laundry basket air pots. I added the extra step of using 8 Zip Ties all around the top lip-edge of each made-up laundry basket pot to hold the two laundry baskets together. For my first ever grow, I invested spent a chunk of money on a few (5 gal size & 12.5 gal size) of the commercially available plastic air pots with their colorful fasteners. I grew, from seed, six plants (2 Auto Fem White Widow, 4 Auto Fem Northern Lights) in these spendy air pots. I needed more pots for my other seedlings, so I made up a few of the cheap Dollar Store laundry basket pots. In these DIY pots, I grew, also from seed, 4 plants (2 Reg Fem Kaya Gold and 2 Reg Fem Blueberry). The 4 plants (Reg Feminized) in the DIY laundry basket pots seemed to grow better and bigger than the 6 plants (Auto Feminized) in the expensive air pots. The difference may have been because of the strains being grown, and also because of my newbie inexperience, so the results I got should not be taken as a criticism of the commercial air pots. I will be using both the expensive air pots and my DIY laundry basket air pots for my second grow this year and will post the results in a few months. These air pots, whether they are the expensive commercially available pots, or your own DIY laundry basket pots, are easy to clean out (I will amend and re-use my potting soil). I wash out the remaining dirt in the pots with my garden hose, then dunk and swish around the pots in a big 30 gallon tub full of water with a bit of added dish soap and about a quart of distilled vinegar, then thoroughly rinse the the pots with my garden hose, making sure all traces of soap is gone, then let the pots dry, and then the pots are ready to be filled up again for another crop. If you need a bigger laundry basket than what is available at the Dollar Store, there are many stores and suppliers (Target, The Container Store, etc.), which sell larger size plastic laundry baskets.
You could turn ordinary inexpensive nursery pots into air pruning pots by drilling large holes on the sides and bottoms and then lining the inside of the drilled out pot with landscaping fabric to keep the soil from falling out of the drilled holes.