cost estimate on default storages of azure-vm

I'm going to plan Azure VM cost and found this link that shows all prices and specs on every VM sizes. https://azure.microsoft.com/en-us/pricing/details/virtual-machines/windows/

This size is what I am looking for.

But after I provisioned vm(with all default option), I can see it has 128GB SSD like this. It's very larger than I expected. here

1. What is the relation between 16GB temporary storage and 128GB OS Disk?
   I thought 16GB is only possible minimum capacity, and depending on the OS installed on VM, real provisioned capacity is dynamically determined(128GB for Ubuntu I've choosed).
2. Is 128GB OS Disk pricing included in $60.7360/month? Or should I pay extra cost for that?
   For example, if I used 32/128GB, then should I pay extra cost(4.81$) like following? here
   Or should I pay 17.92$ no matter how much storage I used? here
3. Is there any option/setting that I can provision only 16GB storage?
   I know 16GB is enough for Ubuntu OS, and I don't need much like 128GB.

Please clarify me.

1. Temporary storage is storage for temporary files that not persisted over reboots or maintenance events. Therefore you cannot store the OS there. More information.

2. The OS disk is billed separately and for the provisioned amount so around 20$ a month. However, you can also use Standard SSD instead of Premium SSD to bring the price down significantly.

3. Using Azure Marketplace images it's impossible to provision less than the minimum amount defined in the image. You could create your own image and deploy that or you could try this. However, that's quite the effort for little gain.

I would recommend other platforms than Azure if you are that price-sensitive (Digital Ocean, OVH, etc.)