You could get a GWR train #GW3866 from Maidenhead to Reading leaving at 9:31 and then change onto another GWR train #GW5414 leaving at 10:04 directly to LGW which arrives at 11:25 - Cost if booked in advance is £30.90 via Trainline.com Total travel time including waiting is 1hr54m which is almost the same time as the route suggested above on the Elizabeth Line via Farringdon but saves you £10