In Previous Days Osclass Pay Plugin is Improving great.
Well! Great efforts by MB themes.
Moreover, I am thinking over how could we deliver Invoice to Buyer who buys the item and To seller by whom it is being sold.
So there could be Function attached to Osclass Pay Plugin for Invoice.

Resources:
1. We have mail delivery Function at Osclass Pay Plugin and also have E-mail template free Plugin.
2. Idea.
     -We can use These two plugins and can make great Invoice generator. Like when we are Updating Status of Delivery at second stage when an item is packed and shipped we can attach PDF file as invoice which contains Invoice.
3. For our Records, we can also send these Mail to over system and can collect invoice to over database. For legal securities.

So is these function can be helpful to Users of Osclass Pay?
Votes require by Reply.

Adding, Suggestions are accepted.

Inoicing is not solved in plugin as it usually require connection to some invoicing system.

As of Now, If someone is selling goods with a classified market with your plugin Osclass Pay, Then how they are gonna use invoicing system?
Need to work on it. Please make one plugin with an invoicing system and connect with Osclass Pay hope it would be a great deal for everyone who is using Osclass Pay Plugin.
Note that Invoicing should have options to avail Tax and shipping charges extra too and price breakdown is also needed in Osclass Pay plugin too. Hope you will update it soon!

Most of companies must have some invoicing system no matter what software / web / script you use in order to align with in-country legislative.