I actually became a middleman for myself and my friends as it made it easier for all of us. I found it better to do it myself first, then offered it to them. The process of sending and submitting is pretty straightforward. The website does a decent job of explaining it. I know in the usa it's $10/card for subgrades. If it's the same thing in the uk, if it's double the price to go through that middleman, maybe easier to cough out the $25 on our own and save longer term on the grading if you want to add cards rather than go through them. Feel free to reach out if you have any questions though, happy to help.