SAVE SOIL…Do not buy soil, make your own soil.
Ideal potting mix for plants
On the bottom hole place crushed coconut shells, walnut shells, ground nut shells…
Fill the entire remaining space with crushed dry leaves and place the plant on the top. Soil coming with plants in nursery bag is enough.
Advantage is, it will save water retaining moisture and dry leaves and shells will convert into slow releasing compost over the period and will help grow more earthworms and other microbes for healthy root growth and plant development.