Microlights can be a cheap option, but isn't necessarily.
I recently returned after a bit of a break to flexwing flying. I paid £2k for a 1/3rd share in a reasonable aeroplane (a Mainair Blade 582 for anybody that means something to), and all-in my flying is working out in that at about £42/hr, in a pretty decent aeroplane that carries 3+hrs fuel and does everything about 50 knots.
If I preferred 3-axis (actually I think they're both great, but am electing to fly flexwings mostly for a bit) I could easily find you a good flyable single seater for £3k, and a fair choice for double that - all of which will probably have £30-£45/hr running costs and operate in the 45-70kn bracket.
On the other hand, there are certainly £60k+ microlights out there which are likely to cost £70+/hr to run when you add up hangerage, insurance, etc. They will however outperform the vast majority of certified light aeroplanes in all but payload. I've been teaching on one just lately - a CTSW, which is a simpler aeroplane to manage, but a much more impressive (and faster) aeroplane to fly, than say a C172 and is costing the new joint owner £55/month + £32/hr wet (plus my time
).
By comparison my joint owned "group A" aeroplanes (both CofA) will cost 2-3 times as much per hour, or about the same per mile and renting a similar aeroplane, 3-4 times per hour, and 50% more per mile. The faster microlights however would beat those aeroplanes per mile as well as per hour, by a fair margin.
For the sheer fun of flying, and doing a lot cheaply, microlights has been the best VFR option for 20 years. The snob value of certified GA, and the fiction of flying IMC & night (well, how often does anybody actually do so?) has made microlights apparently the poorer cousin for years - but it's mostly been a mis-perception.
That you can now rent microlights is a big bonus, although to be fair there aren't many options to do so still, because the microlight community tend to be more built around a culture of ownership.
So microlights are the way ahead if you want to do lots of affordable flying, and the day-VFR restriction isn't too onerous. Many LAA aeroplanes will give similar advantages - although there are pros and cons there relative to microlights: they don't have the option of a Type Approved Permit that allows commercial training, but do deliver hours that count towards an ATPL.
I'm not about to give up the day-job to set up a flying school, but if I did, I could have a Type-Approved 2-seater for £6-£8k that is a perfectly capable training aeroplane, and a full microlight AFI course would cost me about £4k. So, £10-£12k to be able to teach commercially in my own aeroplane [okay yes, under the wing of a suitably qualified FI, but that's do-able] from being a PPL/CPL with enough hours (100PiC of which 60 in microlights), is a pretty cheap way into earning your living airborne. There's a healthy culture of one-man-band microlight schools, or of microlight instructors with their own aircraft latching onto existing FTOs to everybody's satisfaction.
G
(roughly equal hours in microlights and "group A", and currently "CRIing" on both group A and 3-axis microlights so no particular axe to grind.)