What something is worth is determined by the buyer in what the buyer is willing to pay. Sometime the buyer has to be educated to know the true value and sometimes you just to wait for the buyer that values what you are offering.
There are a number of ways that we as cattle raisers can add value to cattle, castrating, weaning, vaccinating, AI, ET, etc. A Bangs vaccine is an extension of that mindset. Any heifer that I think might be retained in my herd or eventually bred and sold is taken to the local vet office for a Bangs vaccine. A few weeks ago, I took in 6 head, and it cost me $34.50 total, less than $6 per head. I don't know how they are making any money at that price, but I gladly pay it to increase the value of the heifers. I also collect a tissue sample using an Allflex TSU and send in for DNA and BVD testing. So far, I have not had much difficulty in selling a few 1st calf heifer pairs. I sold a few pairs last month for $2,000 pair.