Remember, the Thai government does not want you there. Every few months they tweak the policy, then go back to an old law then ignore it. get ready to jump through a lot of hoops.
Remember, the Brits hate you more than the other foreigners who sit at the bar 10 hours a day. If you catch them before 6:00pm they are usually alright.
It will cost around 300baht if you arrive at night. Make sure he uses the meter. Using the expressway will cost you an extra 60 baht but it’s worth it.
Remember, Thailand does not want you living there. They will change the “laws” monthly and every time you go to immigration you will not know what’s up or down. Cambodia is a much wiser choice