I've owned a PA28 140, an Archer II and an Arrow III, by myself and enjoyed nearly every minute of the experience; getting into and flying your own machine is a pretty wonderful indulgence. However, some typical ownership figures based on something on a C of A, flown for 100 hrs P/A, kept outside (don't even ask about hangerage) in the SE of England, are as follows:
Parking (£175 pcm) £2,100 P/A
Insurance £1,000 P/A
Maintenance (1 x annual) £2,000
(1 x 50 hr check) £400
Engine fund (£7.50ph X 100hrs) £750
fuel (£1.50pl x 30 x 100) £4,500
Total £10,750 P/A
Which equals £107.50 ph!
However, if you fly 200hrs P/A, the sum is more like this:
Parking (£175 pcm) £2,100 P/A
Insurance £1,000 P/A
Maintenance (1 x annual) £2,000
(3 x 50 hr check) £1,200
Engine fund (£7.50ph X 200hrs) £1,500
fuel (£1.50pl x 30 x 200) £9,000
Total £16,800 P/A
Which equals £84 P/H!
Clearly there is an economy of scale to be had, whereby the more you fly, the cheaper it gets on an hourly basis. These figures are ball park figures based on a C of A A/C, maintained to the easa version of a public transport C of A, and also assumes that you dont bend it and nothing goes wrong with the avionics or paint or airframe....etc.
There are some good reasons to either join a group or run a PFA machine or a microlight. Personally - and this is a totally personal point of view, from someone who has the means to own by himself - I'm uneasy about groups; when they work, they are a wonderful thing - when they don't, it can be very uncomfortable. As with managing a freehold house divided into flats, the maintenance schedule generally gets dictated by the meanest person in the building.
I think the postee who advised you to get some real-world experience of flying before you jumped into A/C ownership, hit the nail on the head.
Good luck either way you decide!