It's not a bad price if you need oil RIGHT NOW!
However, it'd be a better price if it had an oil filter in the deal.
Walmart has their own SuperTech Full Syn and/or Castrol Magnatec Full Syn for similar or lower cost than $20/5qt jug. Or, for not much more money at W*M($22-$24-5qt jug), you could step up to something along the lines of Quaker State or Pennzoil full syn.
But, as stated, if the oil in staring you in the face and you practically have your hand on the jug, needing oil RIGHT NOW, then grab it. You could easily pay more for a 5qt jug of regular/conventional motor oil somewhere else. Have you seen AutoZone or PepBoys everyday oil prices? Holy Cow!