In the planning stage is when you should decide if the boat itself will play a part in earning income as you cruise. The prospect of chartering may cause you to select a certain type of layout to allow some separation between the hosts and guests. If you are planning to earn income from a trade or profession then you may wish to include a workshop or work space in the accommodation layout. You will have your own ideas of how important the work space is to your future cruising needs. Do not become carried away with this element; you will be better advised to make the work area fit the boat rather than choose the boat to fit the work area!
What is all this talk of working when you are cruising? You may be fortunate enough to have a reliable income to cover your costs. Perhaps you can lease out your house while you are away, you may even acquire a property with that eventual purpose in mind.
It is a wise cruising person who covers many sheets of paper with figures before starting to look for a suitable vessel. After you have what looks like a workable budget you can start to consider acquiring a suitable boat to be your cruising home for the future weeks, months or perhaps years ahead.