The prices of chikoo or sapota seeds in bulk vary greatly online depending on the website which is checked.

In January 2018, the prices of the seeds are as follows:
Chajed Gardens 1 kg seed : Rs 2160
Nursery Live 0.5 kg seeds : Rs 3641 , not in stock
Plantsguru 1 kg : Rs 6100

So clearly there is a lot of variation in the prices of chikoo seeds online