I have always just purchased a Vacuum from a Department Store for around the $100 mark.
Currently I have this
Have owned it for 6 months and it is just not getting the job done carpets are not getting clean and hair is sticking to the carpet I have pets that are indoors often so pet hair does get into the carpet often.
I was looking at the Dyson range at Big W but am completely clueless I have seen people on here discussing different models but not sure what would suit me.
I probably will vacuum twice a week in a 3 bedroom house.
This reddit thread is worth a read; even though he's American, and the discussion is generally US-centric, he gives quite good advice. We've bought a Miele on his recommendation and can say that we're very happy with the purchase!