Maximizing signed Dimaggio/Mantle Balls

I have single signed balls of Mantle and DiMaggio I want to sell, so obviously to get the most $$ I need to get them authenticated.
PSA DNA confuses me. Even after looking at the website. Are there 3 options?
James Spence seems to be another option.
I would appreciate any input to the most cost effective/reliable authentication services to help me do this. I do not have a PSA membership and don't want to have to pay for that, just to turn around and pay them again to authenticate.
Thanks~ Scott
PSA DNA confuses me. Even after looking at the website. Are there 3 options?
James Spence seems to be another option.
I would appreciate any input to the most cost effective/reliable authentication services to help me do this. I do not have a PSA membership and don't want to have to pay for that, just to turn around and pay them again to authenticate.
Thanks~ Scott
0