No, these jobs are low paid because there are immigrants to do them. They can afford that, because they are not going to live their life in the UK but in a country where it's much cheaper to live. This kind of immigration (I'm not against immigration in general and not against immigrants at all, I don't blame them) will always drag down the wages towards Polish levels, but it won't drag the cost of living down, on the contrary. If you can't get Brits to do a job and you have only Brits to do them, you will have to pay more or make the job more attractive in another way.