What 'space' do budgies need? This is important to safely careing for your budgie. I remember a friend of mine when he owned a pet shop in a very busy shopping centre. Walking in I was greeted by the singing of birds and at least 6 birds in flight. Remember this was a pet shop in a very busy shopping centre. Robin believed in giving birds room to move and developed a relationship with them to enjoy their freedom.
If you are unable to give time and attention consider having a cage as large as possible ie:12"x12"x18". It is also very important to give budgies 'natural' perches. By this I mean not uniform dowel that creates a lack of toe movement and encourages long claws.
Look at what Pete discovered
Tough eucalyptus wood makes the best perch your bird could ever have!
Eucalyptus branches also provide trace elements and minerals that are beneficial to your bird’s health. In the wild, budgies are very active in the morning and evening, but spend most of their day resting in the eucalyptus trees and chewing the branches. Natural (unrefined) eucalyptus oil from the bark is also a germicide that stops diseases of the feet in all Australian birds