Been shopping around for folic acid, the cheapest seems to be Holland & Barrett, £1.99 for 250 tablets. www.healthspan.co.uk are doing a special offer of 350 tablets for £2.95 plus £1 p & p. Superdrug, who are normally cheap, are charging a whopping £2.49 for 112.
By the way, did you know that folic acid is the same as folacin and vitamin B9? I didn't!
Also, if preg or TTC you need 400 mcg per day so if you are taking a multivitamin supplement with 200 mcg that isn't enough.