I dropped off a couple books for grading with CBCS Comics, part of Beckett Media. Grading and pressing were quite reasonable for cost but the turn around time for pressing was much longer than anticipated. You can’t fault them for it during the pandemic and I would use them again as things get back to (more) normal, if you did send some in it was about 8 months to get them both back.
The wait is well worth it, both the books came in at a much higher grade than I expected and they were able to remove a blemish on the Saga cover that I was not brave enough to attempt. They also have signature events where you can send in your book, have it signed there, graded and slabbed all at once. If you are interested in an alternative to grading your comics, check out CBCS Comics.