Wow, paying landing fees at your home airfield...if i'd had to, the amount of touch and goes i did before I mastered cct flying, i'd be skint!!
I know it would be a trip around the M25
but try looking into the RAF Halton Flying Club. I hate to think what Clubs around Sevenoaks charge - frightening I would imagine! Membership will be much cheaper, as will the hourly rate, landing is free for club members, ATC is good, the level of training is second to none... and yes, they welcome civilian members (well, the club i'm in does!)