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

Sale price £137.90 Regular price £200.00 Sale
Sale price £111.84 Regular price £146.51 Sale
Sale price £96.50 Regular price £130.00 Sale
Sale price £96.09 Regular price £130.00 Sale
Sale price £46.99 Regular price £50.00 Sale
Sale price £29.95 Regular price £40.00 Sale
Sale price £98.95 Regular price £130.00 Sale
Sale price £50.85 Regular price £70.00 Sale
Sale price £69.85 Regular price £90.00 Sale
Sale price £66.99 Regular price £90.00 Sale