Whoa there Neddy! Back up a sec or two. I see GroundBound resides in Belgium. Now, I guess the costs, labour rates and regs are different there?
Are you planning to own/run a group in the UK? Unless you have deep pockets, I strongly recommend you run your own group if utilisation is low (<100 hours p.a.). Otherwise, you could end up running your C172/PA28 for £200-300 per hour!
Why a group? The hourly and monthly costs are cheaper due to shared costs, plus your engine utilisation goes up reducing further costs. NB: Engines like to be run. If not, there less than likely to reach their TBO without big repair bills.
About 6 is an ideal size. Again, regs on group ownbership are probably different overseas.
Also, landing fees are negli...gab..neg......able...gli...small! compared to the overall cost. Base landing fees can be incorporated into base parking/hangar fees and are a FIXED cost.