The best advice I can suggest is that the choice of who to use for a will depends entirely on the nature, extent and complexity of the estate. If it's simple, then there are free, downloadable wills, or you can even buy a will kit from stationers.
Various charities also do "will months" where they have contracts with solicitors to do "free" wills in the hope that they'll be left something in the will.
If the will is complex, then I'd strongly argue for qualified legal advice, and that may mean not just a solicitor but one specialising in wills. Presumably, this friend isn't complicated or a website wouldn't be an option.
I'm not a fan of wills by website. Either it's automated, in which case you're taking pot luck, or it's "reviewed" by someone qualified, but you have no chance to judge or assess how qualified, or competent.
A "simple" will by a decent local solicitor should be in the £100-£150 range, and the only advantage of websites is saving a few quid. Given the potential for huge cost if you get a will wrong, I see any saving as false economy.
The other option is qualified will-writers. These aren't fully qualified solicitors, but are qualified in estate law and don't need to be qualified in all other areas of law as they specialise in wills. I've not used one, but I've heard good things from friends that have.
As for websites, as I wouldn't use one, I can't recommend any.
