Try the alfalfa king timothy hay in pets at home. Its £9 a bag but its very tightly packed. It lasts ages. And the bag i have currently is the best quality hay i have seen.
Dont be put off by the brand name it isnt alfalfa hay, but they do do a alfalfa type. I have never seen it.
In my opinion, that burgess hay is overpriced average hay. Sometimes below average, and you could just pick fresh dandelions this time of year anyway. Plus burgess bags are not packed much atall, they last not long atall.
Not telling you what to do, but i really dont like burgess anymore