It's much cheaper with a Network Railcard - 22.40 roundtrip. With all HEX tickets, you can use them in any direction (i.e., it's two unlimited one ways basically) and the first is good for 3 days, the second "return" one good for 30 days, so I usually keep a few active for regular trips. 11.20 each isn't bad at all vs Uber if you're time sensitive and already nearish to Paddington.