People don't understand that ps4 could cost $299 already. in 2017, it will be able to cost $199. any company (nintendo included) can release a home console in 2017 or late 2016 for $299-$349 and considerably more powerfull than a ps4.
ps4 power is the minimum we can expect IF the console has a revolutionary thing like he wii. if not, it will be considerably ahead of the last gen.