It’s different in the UK. Those who need a new phone but have limited funds usually buy a cheap or refurbished or used one and get a 12 month SIM only contract.
I get 30G data per month, which is more than enough, and unlimited calls and texts which almost all UK contracts have. Some providers offer free EU roaming as well. I pay £10pm.
I use Vodafone but I never buy through them, they are very expensive. I search around but for me Carphone Warehouse are always as cheap as anyone else and their CS is excellent.