fletcher&murphy

hi everyone. we use sentimol on our dogs but a friend of ours uses Purina total care from wollies at 16 bucks. the tablets from woolies have got everything our tablets have except flea treatment. he puts a flea collar on his to cover fleas. is there something he is missing out on? does anybody know the difference except for price? How come everyone pays so much for advocate etc when these tablets are cheeper? His dog is a shitzu, Murphy and fletcher are cattle dogs x. thanks kate.