Good advice, BigNoseMac.
May I add a comment looking wider?
How are you getting from Bristol Temple Meads to Paddington (travelling in the opposite direction). If you're getting a lift / travelling by coach / doing a weekly Bristol - Birmingham - London triangle, then a single ticket is right for you. But if you're using two single tickets, you may be close to hitting the point at which a super off-peak return at £57.50 - up to the 15:00 off Paddington - is worth considering. On Monday to Friday, there are restrictions from Bristol in the opposite direction on this ticket, but if you're using advance singles that way too, and those prices are creeping up, it may be an option.
Do you qualify for (and could hold) a railcard? On a weekly journey, the 34% saving would be worthwhile!
Do you know two other people who use the same train with whom you could form a group?
I suspect GWR▸ realise they can now fill the seats at a higher price point.
Passenger numbers are ever increasing, meaning fewer opportunities to grab bargains on trains close to peak time.
Your only option to keep paying the lowest AP tier of £15 is to travel earlier.
Indeed. Part of the idea (from GWR's viewpoint) of the Advance ticket is to persuade people who wouldn't otherwise use the train to do so. Also to have those who would use the train adjust their journeys onto services with capacity do so, leaving places on the busier trains open for higher fares.
Passenger numbers have indeed been increasing, but train capacity has not ... yet. It will be interesting to see what happens to prices when London to Bristol increases from 2 to 4 trains an hour. In the meantime, GWR who had expected (by now) to have more trains generating more income, will indeed look to maximise farebox income based on current supply (and demand). It's at their discression, as these are not regulated fares; you may find negative press coverage of the effect, but you'll find a very muted response from government and government owned organisations such as Network Rail, as the problem (delay) in supplying the extra capacity via the GWR main line electrification and stock replacement program lies in their court.
