There are lots of balancers out there, some are more expensive that Top Spec, some less. I feed it because it contains fairly large amounts of hoof growing ingredients. I recently saw an ad for Dengie's new HiFi and Alfa-A balancer. I contacted them and they said I would have to feed their Alfa-A balancer as an equivalent at £24 for 10 - yes TEN kilos. Making it a whopping £48/bag.
It is hard to check which one is better/cheaper because they are all slightly different in the ingredient department. Some also don't seem to taste nice, my horse did not like the D&H one.
You could if you are feeding the balancer swap to the supplement version which is much cheaper but has the same vitamins in it and then use that mixed with a cheaper fibre source.
The supplement version contains less protein and I think lacks the pro/prebiotic bit of the mix so isn't as good depending on your reasons for feeding it.
I think Equilibra is pretty similar but a fraction of the price