Its conveyancing
1. Before you call anyone, ask your friends and family for a recommendation. Always the best.
2. When you call, tell the solicitor what you are buying, how much you are paying, how you are financing the purchase and who you are borrowing from, what stage of loan approval you are at, if you are a first time buyer, an investor or an owner occupier ( for stamp duty purposes), when you would like to complete and the vendors' position on that also ( if you are going to be part of a long chain, it will be considerably more work and aggravation), if you have a surveyor organised ( don't get any survey done until contracts issue as there may be planning issues to address), and whether there are any complications - is it an executors sale, are you aware of any major issues, etc.,etc.
3. Ask for a ballpark figure distinguishing between the actual fee, the VAT @21% and likely outlays.
A lot of firms will not quote anymore - if the client is driven by cost alone then they will simply keep ringing around beating people down on price. A lot of firms will give you an approximate fee quote but will make it clear to you that should the matter turn into a major problem, that additional fees will be charged. On that basis, you either go with a price or a person who comes recommended and who you liked dealing with.
Good luck
mf