How old are you? If below 50 y.o. and you don't plan to work in Thailand you can obtain Thailand Elite visa for 5-10-20 years (600.000-800.000-1.000.000THB). Now Elite visa is eligible for Pakistani citizens too. If 50+ y.o. and you have 800.000THB at Thai bank you can get retirement visa. If you have Thai girlfriend you can marry her but you need to show 400.000THB.
David Broadfoot It is possible not everywhere now: in Pattaya ONLY 400'000 in the bank. Even work permit + salary they don't want to consider at all for marriage visa... To change province or to collect money on my account.
If you have Non-O marriage visa it is the best here already because impossible to cancel and to deport you. And it's "positive impression" visa for any Thai officers on its borders. Else you need to show your work permit together with your passport each time. So don't change.
You have a lot of time to collect money 😉 Pls note that it is impossible to get 1-year visa in Pattaya if no 400'000THB but it is possible in other Thai provinces. Sure you can pay local lawyer around 20k to "resolve" this problem for 1 year. Or you can go to Savannakhet, Laos and to get 1-year Non-O multi visa for 5000THB fee but every 90 days you need to go on visa-run for next 90 days border stamp.
I have got same visa from Savannakhet. Yes, it's for 1 year but foreigner must go abroad every 3 months. So this kind of visa is possible for 15 months in fact, no financial requirements but not so comfortable to live.