The Xiaomi watch is well priced at £200 ish delivered to Europe considering it has an e-SIM, I'm unsure about support for the e-SIM in Europe.
Aganst Apple Watch entry level Series 3, not cellular - starts at £189 or used ones around £120. Latest series 5 is about £400.
I've used smart watches since Pebble and find them incredibly useful. Currently a £28 Mi watch imported from China. I'm considering a low cost way into Apple watch ownership but it's hard to throw away a 1 month battery life for a 1 day battery life. Especially for trinkets that have a life of about 6 years from new to landfill.