The cheapest way of getting good availability and minimising cost is with a group-owned syndicate. A permit aircraft will cut the costs even further especially if you're willing to use your own time with things like 50 hour checks.
That way you share the cost of hangarage, insurance, annual inspections etc which form a large chunk of overall operating costs.
Have a check on the notice boards at local airfields and ask around. There are often a lot of shares going that you don't see advertised elsewhere.