just to throw a spanner in the works i know of a team that aimed for 5th rather than 6th then sold all his players, sacked all of his staff with the last week of the season still to go and the position locked up and now plans to have close to 0 costs for the next 4 weeks - that is a saving of more than a million and they were able to sell their players at a premium before the trade deadline
In a lower level league this tactic could be godd,but if you play at higher level,it's often difficult find on the market the players with the salary/perfomance ratio that you need for playing your league next season,you take a lot of risk before while you're searching the right player you can lose many games in the next season,so losing other money
#in addition i hope this won't become the most have strategie for this place, and when lot of people do it it will also become a very cheap transfer period and very expensiv to buy them back at the beginning of the season.