From my experience you do get what you pay for, & this shows itself with things like suspension parts that have ball joints etc.
We have a Ford Galaxy (Alhambra/Sharran type). Notorious for going through drop links on the front suspension. Dealers sell them for about £40 each. Can get them for as little as £10 each on Ebay. The Ebay ones last 2-3 years. The originals had been on for 6years when they went. Would I have been better off buying the £40 originals…? Its a 15min job to change them (dont even have to take the wheel off).
I’ve bought a complete set of discs & pads for the Mondeo for the price of a set of pads from the main dealers. They’ve been on 3 years now with no issues.
The only surprise has been the new front hubs for the Mondeo. Dealer wanted £120 ea. Pair from Ebay were £75. I half expected them to go again in a couple of years but 3 years on they are still sound.
For something like a clutch I wouldnt scrimp. Given the box has to come out I’d buy the Borg kit, & a decent slave cylinder also.