Appears you're getting a flood of responses
Condition, condition, condition of the endura nose & grilles, as well as who the seller is dealing with (body shop/insurance job), as well as location play a HUGE factor in what a fairly nice '68, '69, or a 70 endura will actually sell for. Bent, twisted, & the absolute worst, suncooked & crumbling... not worth much. A good percentage of the nice endura bumpers Ive sold over the years have been to restoration shops & body shops I've dealt with for a long time. For individuals, being a large oversize part that takes quite a while to properly package & usualy requires being shipped truck freight, been my experience that its often been easiast to meet up with individuals when I'm on the road or on the way to a national show.
Properly prepared for paint, I'd value a restored '70 GTO bare endura @ 2000-2500. Its not a walk in the park to get even a nice core '70 endura ready for paint. Thoughts on other related parts... on the grilles, whether selling or buying, what do the chrome surrounds look like, are they pitted? Any broken mtg tabs? Really decent used, its possible to pay up to $450 a pair, the chrome won't be perfect though. '70 headlight mtg plates seem to show up fairly cheap, so do the reinforcements. In June, I picked up a fairly clean bare '70 GTO endura, it's not bent, gouged or crumbling, top line is straight, corners are not cupped, such core noses have to be decent cores or I wont mess with them. Already had in stock pair of nice used grilles, frame brackets, headlamp mtg plates, nos headlamp bezels. Picked up the bumper reinforcement from a racer client that had fabricated an alum structure to save weight. Ready for proper refinishing this winter, have two Firebird endura's, a '71-72 GTO endura, as well as this '70 endura to properly prep, hopefully can get to them one after another.