I don't know if anyone will want your injectors. I purchased some used injectors for my car, (stock 2005 blacks) had them serviced, installed them and found my stock 2006 ones to be blue. So, I used the blacks until the blues were cleaned and balanced and switched them out. I put the blacks up for sale for the price I paid to service them. Not what I paid for them or the sum of both. For the price of having them cleaned and balanced no one even made an offer. You may have better luck but I wouldn't put a penny into making them more attractive to a buyer.

Les