For reference, you're looking at £950 for the DMF and clutch from VW, before discount. If your dealer is a good one, it can reduce to about £600 for both. Big metal parts have bigger discount codes than the smaller stuff. Just have to ask.
I've compared OEM and aftermarket supplied clutches of the same brand, and there's no comparison. OEM LUK flywheel lasted 95K miles. Replacement LUK from ECP put in 2 years ago is dead already. It's just the small things like pressure plate balancing, pressure plate spring consistency, throw out distance etc etc. LUK/Sachs are not obliged to make their clutches to OEM standards for the aftermarket....hence the price difference.
In the spring/summer I will be doing TTRS pressure plate, OEM friction plate and OEM DMF. I can't be arsed with dropping the gearbox every 2-3 years to replace shoddy flywheels. You may not have any trouble with that ebay clutch, but I highly doubt the DMF will last long.