Pros & Cons
Liz,
There is a lot of good advice that you have already received on your post, perhaps my two-pence worth might be helpful.
I obtained my PPL(A) after retiring in 2001 and continue to fly both out of Barton and Liverpool. I personally do not like Pipers because they generally only have one door at the front. I need to assist my wife into and out of the aircraft and this is very tricky with one door. Also, if I ever had to make a precautionary landing it would be impossible for me (sat in the left seat) to get out!
I started learning at Liverpool but finished my training at Barton (with LAC). I personally never take passengers from Barton because it is very bumpy, preferring instead to take them out of Liverpool.
Mainair at Barton are considerably cheaper than LAC or the Flight Academy at Barton. But you are looking at the microlight type of aircraft. Louis Blanchett is one of their instructors, I know him very well and did my PPL(A) completion with him - can't recommend him highly enough.
Lomac Aviators at Liverpool is a very friendly place and Neil Hazlehust is a very good instructor.
I know all the instructors at LAC Barton, Martin is good, but so to are Francis and Tony. I did my PPL flight test with Francis and she is excellent.
The costs of becoming a Commercial pilot have been understated in previous posts and those who have the qualifications still can not get a job. I know commercial pilots, one or two trained with me and the cost is between £70K-£100k.
I used to have a share in a Cessna 172 at Barton but this has been sold, so at present I operate via Lomac and SMAC (Southport & Mereyside Aero Club) aircraft at Liverpool.
There are advantages with Barton, much more friendly than Liverpool, no commercial traffic to concern you, much more a General Aviation airport. Disadvantages are it is grass and very bumpy, and they use FISO's (Flight Information Service Officers). This means that Air Traffic Control (FISO's) give you limited information and instructions. Fuel at Barton is also much more expensive than at other airports.
Liverpool is less friendly but tarmac runway (much longer than those at Barton), full Air Traffic Control and you are "mixing" with Ryan Air and Easy Jet. Really it all depends on your preference.
Hope the above is helpful, if you want any more information then PM me.