Like I previously said I get mine in a one tonne bulk bag from hi-peak. This works out very reasonable.
https://www.hipeak.co.uk/product-category/bulk-feeds/ price is not on there however I think it came in around £400 ish for 1t you pay around £50 for delivery on pallet.
I had a recent bad experience with ordering organic layers and after checking the contents found it was just soya and wheat - no wonder they werent laying and were getting loses. Not happy either by the high amounts of soya in their food.
The Hi-peak layers contains a great variation of mix and once they were back on it laying back to normal. Contents include wheat, corn, linseed, beans, oils and vits.
Buying in tote bag makes the price more competitive. I prefer buying a quality mix like this as I havent time to be adding to the mix or worrying about them as mine as pasture raised organic eggs and are a commercial business.
I would always compare a homemade recipe with one commercial and if you start messing you can make grave mistakes with nutrition level. If you are struggling with costs then your retail price needs to reflect this.
Its important when selling overheads are accurate and do get fed up when I see the ridiculously low price some people put on 6 eggs we like every other business are not a charity and you have to price in labour, feeds, meds, labels, boxes - sorry for rant!!