As said, the solicitor does not go to the probate office. I took out probate a few years ago & it was very straightforward - you go in & have a meeting with the probate officer & they will list out all the assets etc. Once you & they are happy, you get some forms to go to Revenue & then back to the probate office - I did the whold thing in about 4 or 5 hours.
However, you probably need to check what agreement you have with with your solicitor as you may already be comitted to having them finish the whole thing for you. You could ask them what would be the bill todate & what would it be if they completed it.
My solicitor asked me to gather all the paperwork (which is the hard part) & to come back to him at that stage. After doing all the donkey work, I checked out what would be involved to complete it myself and realised (as the estate was fairly straight forward) i could handle it myself. Saved a packet (about €40k if I recall correctly).
If it likely there could be complications, I would stick with the solicitor, just make sure you know what you will be charged.