Possible Clues:

• Sustenance
• Cost of living at university?
• Cost of preventing deterioration
• Service charges for castle in the air?
• Look up a little at what it costs to maintain
• You could get it up to look up for maintenance
• Just look up the cost of maintenance
• Take a peek up at the castle to see what it costs to maintain
• Look to retire on winning maintenance
• This will maintain a look-up