Based on the search results, I would recommend either the Pampers Premium Care 104 Nappies Size 4 Mega Pack for R429 or the Pampers Baby Dry - Size 4+ Mega Pack - 120 Nappies for the same price of R429. Both of these options from Pampers would be excellent for your 18 month old baby as they are designed for toddlers around 12kg-18kg. You get great value with either pack, receiving over 100 nappies for under R430. Pampers is also a trusted brand that is known to be comfortable on delicate skin. Let me know if you need any other details, otherwise I hope one of these packs will work well for your little one!