Just to add, I would advise you to use caution when trying to purchase one of the £3 TOC staff day rover tickets from the drivers on the RA2 - and treat being able to pay the £3 fare as a bonus, rather than an expectation - particularly if you're travelling with someone else.
As you may be aware, family and friends travelling with you are also entitled to the £3 fare, however in my many experiences of using the RA2, around half the time I seem to run into issues with clueless drivers with an attitude that I would certainly get pulled up for if I used in my job.
Even with the letter of authority from SWR, which we had been instructed by the union reps at my depot to show to the RA2 drivers (as it is a known issue that the drivers like to refuse the discount), some still outright refuse to issue the discount, and if you argue with them enough, they may offer you the "railcard rate" tickets at £7.
I've complained to First Bus countless times about this (and the generally poor service on the RA2) but nothing is ever done about it, and I've now given up with using them unless absolutely necessary, as having to argue your way to a discount you're entitled to puts a bad taste in your mouth for the rest of the day.
I'm not saying all of this to "burst your bubble" (for want of a better term), but I just don't want you to get your hopes up if you end up in a similar situation.
And I mean no disrespect to the RA2 drivers, as I have encountered some fantastic ones, but unfortunately there are a handful who behave with an attitude I'm astounded they can get away with.
I wish you all the best and hope that it does work out well for you.