I moved back to the UK from Thailand nearly twelve years ago. I brought my Thai wife with me and our son who was then seven. We settled in Surrey but very close to South West London where I had lived before. We were then guided by Offsted reports to get our boy into a good state school.
I know Brighton very well and we often go there for weekends. I have a very close friend who lives there with his family. Firstly, using Brighton as a comparison is ludicrous, as it has house prices close to Central London, along with 5* restaurants on almost every corner. Pattaya is way off of mark for any Thai comparison. Silom in Bangkok would be closer the mark but still a poor comparison.
I would suggest that Southend on Sea is more in line. Lots of cheap places to eat and a raucous and rowdy nightlife. Plenty of drunks vomiting up their shish kebabs and party girls staggering about and peeing on the seafront. Away from the seafront, there are numerous B&Bs for all budgets. (My apologies to any Essex ex-pats in Thailand, I am simply painting the picture). And yes I do know Southend, as my sister lives in Hockley, just down the road.
My wife still visits her family in Thailand and often stays with our friends in Chiang Mai. According to her, the smart restaurants are very close, price wise, to the ones near us. Hotels are less expensive in Thailand for what you get, compared to the bigger chains in the UK but budget hotels like Travelodge and Premier Inn tend to be cheaper.
House rents on the other hand are much cheaper in Thailand apart from parts of Bangkok and Phuket. Food in the markets is obviously cheaper,but the supermarket prices are quite comparable. Wine in the UK is cheaper but Beer is more expensive.
But quite honestly, these comparisons are rubbish. Whatever I quote, somebody else can quote something different. The only thing I would say is that, at the moment, Britain is going through all sorts of serious problems caused by different factors, including, the war, massive inflation, global warning and the disastrous effects of Brexit. So for now, I would sit tight in Thailand if I were you.