At today's exchange rate I get 38,500/month for my UK state pension.
It's 40kbht/month income required for a marriage extension.
Not what I would describe as 'far short'.
(Expecting a 7% rise to be announced in August ......... so 41,200bht/month in 2024 )
But like most other people I just keep 400kbht in a Thai bank account, so no monthly income at all required.