FWIW the return wells always seem prone to plugging. The hardness in the water will drop out in low pressure situations (like after a CSV), eventually causing the return well to lose acceptance rates and generally making a mess in the yard.
Again, function of water quality, also when we do it, we install a pitless unit and piping inside down below the water level in the return well....that way, you don't aerate the water and cause iron and such to precipitate. Another problem with return wells is that people try to be cheap, and don't install a good well, or develop the well properly. The return well is just as important, so we drill a mirror image, and develop it the same way. A lot of folks try to go shallower, and put it back in another aquifer to save money on the return well.....it never works. I know of lots of return wells that accept in the hundreds of gallons/minute; almost continuous for years, no problems.
Cost for a return well....I'd be about $6000-6500 for a 370' well, fully cased and screened, gravel packed, grouted and developed.