This sounds ridiculous. YANBU.
In your shoes I would work out what I could afford, tell her what I could afford and that would be that.
You cannot hire the hall for them. If there is a fee per night and you want to stay there, then do, for as long as you want to. Just say you cannot get the time off work and you cannot afford the 'fee' per night for too many nights.
As far as the dress and shoes etc, when I got married I bought the dresses and flowers for my bride's maids, I think a hairdresser came to the house for a relatively low fee and 'did' our hair, and we did our own make up or each others! Everyone got a bracelet or something as a thank you gift for being a bridesmaid and they wore their own suitable sandals. If I remember rightly.
Can you afford all this? Will it affect you, e.g. loss of your annual holiday because of it, or will it be something you can stretch to, your choice, of course.
Frankly, your friend is taking the piss, no one except the most noticing person (to use that Agatha Christie phrase) will see the shoes, or care, and I would hazard a guess the same for the jewellery.
She is your best friend, your words, so I would engage in a frank and friendly discussion with your friend and explain you simply cannot afford all this. If it were me I would say something like when you agreed to be chief bridesmaid you were very flattered and very happy to be with your friend on her special day, but the costs are mounting up and it is not possible for you to do all the things that she is asking.
Either chose the bits you want to do (hen do, nice shoes etc) or the bits that are important to her (your choice, I would go with what will be useful for me - e.g. will you ever wear those shoes again! I only wore my wedding shoes about once again, but they were inexpensive and I paid for them myself! Or maybe my dad did!!
Anyway, all best wishes, above all you probably do not want this to affect your friendship but I wonder if you will find this does affect it if you spend a lot of money and feel unhappy about it afterwards.