I have a PAYG oyster card and a YP railcard.

I normally make off peak journeys. I was very surprised to find that
90p had been deducted for a journey from Burnt Oak to Camden town!!

I used the single fare finder and indeed a lot of the fares have
become cheaper. Why is this??

Also I am still confused about the peak and off peak cap.
I used to buy the paper Zones 1-6 YP discounted card @£ 5.00 thus
knowing I could travel back at peak times and not pay any more.
What is the situation now if I make at least one peak journey and 1
off peak journey using several buses tube etc?
Can you still buy the £5 travel card?