Akallabeth, we followed a similar plan to what you propose, except we really didn't have a plan. After a hiatus of over 20 years when we had sailed an 18' catamaran on weekends for a few years, we decided to come back to sailing and took monohull courses including coastal navigation. We then rented boats for half-day sailing for a while and later joined a flotilla in Greece with a UK company. We tend to be a bit reclusive but discovered we really liked flotillas, and along with renting we "successfully" avoided buying a boat for about three years.
Although still being convinced that it did not make sense economically, we bought a boat about three years ago and have not had even one second of buyers remorse. Beware. Part of our justification was no more European vacations, but we haven't stopped those either and have already signed up to return to Greece in May.