Buy a Zenair 601 with 200-400 hours on it with a Rotax 912, fly 100 hours a year, sell it with 400-600 hours and - if you have serviced it well and kept it clean (we all know cleaning an aircraft helps you find defects early!) - you'll get your money back.
Yes, you will have servicing costs of anything from £100 a year to maybe £1000 a year, and then you get your money back!
Or buy a Cesspit and pay 7k a year for a CofA or whatever it is called nowadays, and then really struggle to sell it, and run the risk of a major mandatory mod that will cripple you.....might be cheaper just to scrap it....
ps. Weightshift microlights now do 100 mph, LAA (and some microlights) will do 140mph (Statute) ! So no hanging around floating in the sky!