Around £3k a year renting. Others will be along no doubt to say that with that little flying there's no way I can ever be safe, but we're not all as rich as them.
Depends what you do with the 3K. If you bore the same holes in the sky in the same direction every time you fly (not suggesting you do by the way) then you're not going to get a lot out of it in learning terms. If however you try to for instance visit at least one new airfield a month then you're increasing your experience and skill levels. You can do a lot with 3K if you put your mind to it, and I'm sure you do. Of course if people are happy just to go for a sunday morning bimble to the same place and back then no one has the right to criticise that; their money, their choice.