Please do not call the airlines! Once the airlines know about the mistake they will fix it and this deal will not be bookable any longer. Don't even call for seat assignments.
Etihad/ Air Seychelles currently have a business class fare published that is just $343 for the one-way from Seychelles island to Dublin.
You can look up available dates using the 30-day search on ITA Matrix. Generally every second day is available with 2 seats.
Both legs are in Etihad aircraft. Etihad has a great business class equipment and service.
Regular prices for the one-way are about $3,000.
This fare only works as a one-way from the Seychelles to Dublin.
The fare can be changed for $50 and cancelled for $150.
You can stop over in Abu Dhabi. It's close to Dubai (1.5 hours drive) and the stopover will just slightly increase the price of the ticket.
I was only able to price it correctly including stopovers on opode.de. It's a German OTA but the company has provided excellent service to me with the last mistake fare (Burma in 2012). So I'd be very happy to use them again. Use Google Translate to figure out the booking process.
Also note that both legs should be in Business Class and that your second flight is marked as sold and operated by Etihad. This way you can earn AAdvantage miles instead of just Etihad Guest miles.
It is possible that Etihad/ Air Seychelles will negate the booking and cancel it. Each mistake fare has a different outcome so there is a chance this one will stand. As more people book as higher usually the chances that they will honor the fare.