Amazon is having a two for $30 sale on selected TV shows (146 titles). I've only listed the Dr Who's and Russell Coight's DVDs below.
Free shipping with Prime (not sure if $49 spend applies).
Doctor Who: War Machines - $5.24 (was $19.95)
Doctor Who Web of Fear - $5.24 (was $19.95)
Doctor Who: Underwater Menace - $5.24 (was $19.95)
Doctor Who: Doctor Mysterio BD (blu-ray) - $5.24 (was $19.95)
Dr Who: Pyramids of Mars - $5.24 (was $19.95)
Dr Who: Survival - $5.24 (was $19.95)
Doctor Who: Image of the Fendahl - $5.24 (was $19.95)
Doctor Who: Vengeance on Varos Spec. Ed. - $5.24 (was $19.95)
Doctor Who: Twice Upon a Time (2017 Christmas Special) - $9.74 (was $19.95)
Doctor Who: Christmas Special 2015 - $9.74 (was $19.95)
Doctor Who: Power of the Daleks - $9.74 (was $19.95)
Russell Coight's: All Aussie Ad: S1-2 - $12.98 (was $19.95)
I never go into the outback without a decent supply of water, and the general rule for how much you'll need is: three litres per day, per person, per man, per degree over 25 degrees celcius, per kilometre if walking on foot, in the winter months dividing it by two, plus… another litre… at the end