I doubt they are the ones looking for stuff here or aliexpress, or they would just build better from scratch, no?
Yes. If they're Alexpress shoppers, they should get an eGR for $300 or less. That $300 includes the calipers, hoses, barbs/fittings, and levers. Oh, yeah, and an electronic derailleur. I literally put that on my Poseidon. Foolish not to, if you want to spend money upgrading a bike like that, do it properly.