Any recommendations on this topic.? I have done both and still not sure what is the best.
In a shop I managed to get a £150 phone for free because I said I couldn't afford the phone at that point and would wait until it was free, but the sneaky so-and-so's put on additions to the price plan without telling me (I was green then).
On-line there is no hassle about add-ons and insurance hard selling. But it does seem price plans differ even from the providers own shops and websites, including what number you have to phone for customer support.

Online I find best. I find it cheaper and easier and always buy SIM free phones so they are not branded or network locked.

It depends what you want.

If you already know exactly what you want and are happy to receive a box and a book on instructions on how to use in the post without advice, you will probably find on-line prices are cheaper as there is minimal labour and other overheads involved.

If you need advice on which phone or deal is best for you, would like the option of feeling and handling the different models available before making a decision, or would like assistance in understanding how to set up, use and get the best out the the item you decide to buy, then buying from a store is probably the better option.

Whilst the store people should provide the help and assistance you require, someone has to pay for this service and that has to be reflected in the price you pay. Also these people are salespeople whose job it is to prise whatever hard earned cash is in your pocket and ensure it ends up in their till.

Buying a mobile phone really is no different to buying any other item or service in this respect.