I have these ingredients

[karpes]

I have been using 60% cheap cow manure compost ($1.30 #40 bag) and 40% Peat with fairly good results but I am trying to improve the mix this fall and spring. All will be grown in 5 gallon grow bags/buckets in the greenhouse this fall and outside in the spring of next year
Here is what is available to me from Lows and free.

3.8 cubic feet peat $10
2 cubic feet pine bark compost $3.02
Rice hulls (not composted) unlimited supply
Horse stall bedding (raw uncomposted) unlimited supply
Fired clay pellets (light concrete mix aggregate used in hydroponics) $32 per cubic yard

I know the horse stall bedding is going to be hot so I am having second thoughts about using it without a chill period but maybe just a little?
For the outside containers I plan to continue using the Mittleider method with timed irrigation but in the greenhouse I will be using fertigation with 20% run to waste.
The cow manure compost/ peat mix, if my math is correct runs me less than $1.50 per 5 gallon container but I believe that with your help we can come up with a better mix at about the same price or even less.
I have experimented with coco coir with excellent result but it is just too expensive to use when you are filling 40 containers.
Your thoughts?
Karpes