To put this into perspective after the first 100 chunks are uploaded on the network the cost is 1 / 1.2676506e+30 Then this is offset by number of users which will increase the cost proportionately. So it’s unlikely the cost of uploading 1Mb will be any more than 0.00000000001** as an example.** Not conclusive maths here, but just pointing out the 1 coin per store is first chunk on network only. 2nd chunk is 1/2 third is 1/4 fourth is 1/8 and on it goes. It should be a tiny amount in practice.
Hope that helps.