Apart from fairways, traffic separation zones, undersea cables, etc., you can anchor where you like. In practice, you want to anchor where it is calm and not too deep, with firm mud at the bottom. Keep an anchor watch to see if the anchor is dragging.
Thanks for your comment. It is an average figure or estimate. There is the recurring cost of antifouling and engine maintenance. When the boats get older, you might be looking at engine overhaul or replacement; new sails; new rigging and electronics; etc. If you have the tools and know-how, you can save money by doing the job yourself. If maintenance is bad, that will be reflected in the selling price , when you want to sell her. So, it still boils down to money. What is your personal experience of the maintenance cost and the type of boat that you own?