I had a similar situation last year and found an OEM part online from Land Rover Reno for $120. A local body shop charged about $100 to color match it. The flare was listed as fasteners-included, but the flare arrived without them so I had a little delay waiting for everything to arrive.
While waiting, I removed my cracked flare and pulled the cracks together with Gorilla tape on the interior surface. You could barely see the cracks once remounted.
As you probably discovered, there are a few fasteners to remove before popping the flare off - plastic push-rivets at the top and rear of the arch, a screw at the front, and a hidden screw accessed from under the hood after removing the grill and headlight. With your flare removed you’ll be able to see what broken clips/fasteners you’ll need to order for whichever new flare you source.
Getting a painted flare from another member sounds like a great option.