Really depends on your horse - it's a total false economy to feed rubbish quality feed, as you're only causing problems for him in the long run. Ensuring his diet is high fibre, possibly using a dengie alfa-a product to keep a high fibre diet with reasonable energy too. What kind of work is he in? Is he in or out? Many companies have economy mixes which are just fine for reasonable do-ers in light work, but it really depends on your horse and what you want to do with him.

basic pony nuts and own brand chaff. The only thing with that it may not suit your horse or workload.