The last time I went into it (about 15 months ago) the fixed costs of owning a single engined aeroplane was in the region of £5000, ie £100 per week for insuance and hangaring.
This excludes the actual flying time costs and unexpected wear and tear and unexpected big bills.
The more you fly the more this overhead is spread out and the hourly rate becomes lower.
Believe it or not, you will fly less than you think in a year... I am considered pretty active... just under 100 hrs last year.
This is where group flying comes into it's own... you all share the fixed/maintenance costs and pay for your flying individually.
But be careful... groups are like marriages... make sure you are happy with the other members.
Also make sure that they will be able to accomoadate your flying ambitions... you will probably be buying a share from someone who has lost interest and has not been active, therefore the others will have to make way for new active member.
Make sure that the vendor isn't selling up because he/she knows of a big bill on it's way like an engine... don't get involved with an engine on an "extension" unless the share is VERY cheap.
Sorry to go on, I could probably write a book on group flying if I haven't already.
Oh yes... you are doing the right thing in thinking ahead about where, when and how you are going to continue flying when you get your PPL... too many students drift away after qualifying.