Your search for "potassium citrate effervescent tablets" revealed the following:

Sale price £49.99 Regular price £70.00 Sale
Sale price £12.99 Regular price £20.00 Sale
Sale price £42.95 Regular price £70.00 Sale
Sale price £49.99 Regular price £70.00 Sale
Sale price £28.67 Regular price £40.00 Sale
Sale price £69.50 Regular price £90.00 Sale
Sale price £48.61 Regular price £60.00 Sale
Sale price £38.99 Regular price £50.00 Sale
On Sale from £35.50 Regular price £40.00 Sale