Hi,
2. No, you only want to send him the notification at the end of the auction, when you know the winner of the auction so that he has a payment link to send the points to the winner of the auction, right ?
3. If you want us to work on that project for you, that's possible. You can use our contact form to request a quote:
www.hikashop.com/support/contact-us.html
Make sure that you specify exactly what you want us to work on.
Now regarding the 2/3 lines of code to add the points, what I mean is that the code to add points to a user in easysocial is only 2/3 lines:
$eas_points = FD::points();
$userInfo = FD::user( $joomla_user_id );
$eas_points->assignCustom( $userInfo->id, $points, 'reference number of the auction' );
And that's just for adding points. You need also to remove the points from the vendor account with similar code.
Of course, you need first to load the user ids, check that the auction is closed, that the user doing the points transfer has the right to do so (logged in, etc), you need to load easysocial, and you need to do all that in a controller task. So it needs the development of a proper plugin. It's not just 2/3 lines you can add somewhere in HikaAuction and it will work. The total plugin code will be 200 lines I suppose. And you have to customize the email notifications code too in the System>Emails menu. I actually checked the code of HikaAuction and it will require a few patches in HikaAuction too to be able to override the receiver of the email from the preload section of the email so that the email goes to the vendor and not to the winner.