Unfortunately, wills are an unregulated area. This means anyone can set themselves up as a will writer, including solicitors and charge whatever they want.

Unlike LPA's, a will is for when we are no longer here. A will spells out your wishes of how you would like your estate and anything you own to be dispersed to people/organisations that you wish to.
It is your assets, you should choose where they go (or not go).

If you don't have a will your assets may pass to the state or to others which you may not have wanted to leave things to.

Wills can be very complex or very simple. The main component though is - they do what you want them to do and are written in such a way that they do not fail.

There are lots of rules around signing, who can be a beneficiary etc. If you are attempting to do this yourself, please do some research. 

A lot of charities offer a free will writing service with the expectation that you will leave them a gift in your will. Some of these services will attempt to sell you additional products such as trusts. This is fine if you understand what they are.
If you choose to leave a gift to a charity you could consider leaving a fixed amount, £500 for example. If the will writer puts a % of your estate, it can make life challenging for your executors and beneficiaries as the charity may contest the amount a property is being sold for which can delay the process. It can put undue stress and anxiety on everyone who are already grieving.

Wills can differ in cost depending on the complexities. We are unable to give you an accurate quote until we have had an initial chat. Like most of our processes though, we try to be cheaper whilst offering a high quality service, mostly in your own home.