Facts of life--parts (new & used) will only get more expensive over time. An out-of-production vehicle is an opportunity to raise prices, as it costs manufacturers more to produce smaller quantities of replacement parts that are application specific--prices go up to maintain equity in the effort (ie. profit).
Fortunately, many of the front suspension parts used in the B-body are common to a number of vehicles & years, with a fairly sizeable population still on the road, so demand is still there, even though cars/trucks using the parts are mostly out of production. 73-77 A-body, 77-up B-body, 70-81 Camaro, 75-79 Nova, 78-88 G body, S10 pickups, and Astro vans share(d) a number of parts--only Astro remains in production, and running gear/suspension has been revised, so I don't know if it still has any commonality with any out-of-production vehicles. Lower ball joint for Astro was same as Moog K6141 (5/8") as an example.
Moral: take care of your stuff, plan ahead. Remember, no one feels sorry for orphans in the car business.
Check vendor section, for starters:
and there may be others. Have you checked with Dal?