dalef the answer partly depends on your skill set and the opportunities near you.
If you are good with mechanical bits and pieces and can afford 5-6k, then you could buy an LAA single seat aircraft and the chances of a big bill would be almost zero as you would do all your own maintenance etc under LAA supervision. You are very likely to get back what you paid to purchase it provided you took care with the maintenance etc. Such a machine is likely to cost around £300 third party insurance, £600 in maintenance, burn 10plh of Mogas and cost around £1000 a year in hangarage provided you can find a local strip.
Another possibility is a share in something local to you. This will reduce the “big bill” risk as any expense will be split across all the members of the group. Some groups do not like hour builders, but some are desperate for people to fly the aircraft. A single seat aircraft like the one mentioned above split say 5 ways is very cheap flying.
The US 150 has already been mentioned and a solution I do not know much about.
Rod1