Here in reach is idiomatic, common, and means attainable,
Ex: Obama Says Nomination 'Within Reach'.within reach = in reach = attainable = within the bounds of possibility , come-at-able, accessible, get-at-able, approachable.
1. ... taking whatever of their aunt's came within reach, or what they could get.
2. ... it should be in reach of the average customer, or be able to reach with one's hand.
3. His explanation is beyond my reach; i.e., another way of saying I can't grasp or understand it.
Student or Learner