I started gliding three years ago so am still a novice but my experiences are at least recent so thought I would give you my viewpoint.
An aerotow gives you more time to learn the basics of control before getting into the hard bits (take off and landing!). I suggest you learn both methods if possible as a winch launch on a good day when you can “get away” is a lot cheaper alternative once your skills improve.
The club I am learning with charges £17:50 for a 2000-foot aerotow plus 29p per minute for the use of the glider. All instruction is by club members so free of charge. Once you get to the stage where you are doing spins etc. then it is usual to take a higher tow to allow a series of exercises. We have a £5.50 winch charge whatever height is achieved and the annual membership is £190.
The time of each flight is very dependant on weather and also the tasks being performed. When doing cable break exercises my log book has several 1 minute flights logged and even two at 0 minutes!
For an hours flight from a 2000’ aerotow in one of the clubs glass single seaters the cost is less than £35.00. If you use the older wooden glider and managed an hour from a winch launch this would cost only £14,50! Of course this is very dependant on conditions and a typical 20 minutes from a 2000’ aerotow would cost £23.30.
Most clubs will expect you to be an active member rather than just turn up and fly, so be prepared to spend time on the ground assisting the operation. Some people find this a problem but others find it a very relaxing way to spend a day in the fresh air!
I suggest you simply visit a reasonable large club and spend a day seeing what happens and decide from there. I also suggest you start with a day course rather than a simple trial flight or gliding experience as you will get a lot more for your money.
Once you are solo it is just the beginning so there are always new targets to reach for. I hope you get as much out of it as I have.