The problem is that they leak, the tops of the bottles need to be placed on perfectly (easier said than done), otherwise you can be sure you will either spill it when you shake it or when you are feeding. My recommendation would be stay away from this brand of baby bottles no matter what the discount is. The bottles were bought from mothercare (yes again).
Apart from avents bottles I have never had a problem with any of their other baby equipment, in fact we use their baby steriliser which I will cover in a later article.
If you don’t heed this warning you can buy them for in the region of £15-£20 for 4 bottles