Smithy is right, there will be 1000 answers to this but cost aside, what do you wish to do with your PPL once you have it? If you are going down the career route you will probably end up with glass anyway but what about when you go for complex and twin, will that training also be with glass? Probably not..
If you wish to remain PPL, unless youre buying something with glass, dials are what most clubs rent out and at a cheaper rate.