It’s really depends on the area you live in . Where I live it can very by yard . some yards are as cheap as €400 per month and some are as expensive as €480 pre mouth for full livery without the riding. It also depends on what type of livery you are doing DIY is way cheaper.
I'm no sure it really depends on facilities either to be honest. I charge more for grass livery with storage and good hacking than a yard up the road with lots of facilities. I think a price is only what someone is prepared to pay for it. I wouldn't want be on the big yard up the road so I don't think their price is value for money.
I'm Devon and my understanding is that the price for DIY livery is around £25 per week per horse; I'm advertising my yard currently and that's what I'm charging. This includes livery sole-use of field and two loose-boxes. Sharing yard with me. Own tackroom, room for feed storage. Sharing yard with me.