My first renewal of my marriage extension is coming up and I have to top up the 400,000 baht. I play the fools game and try to bring in the money when I think I can get the best exchange rate. Is it still 2 months that the money has to be in the bank before the extension? Also if I leave the country before the extension date (with an exit permit?) but may not return until after that date, do I have to start the whole process to get the marriage extension anew?

It is 60 days for extensions based upon marriage. There is no 60 then 90 rule.

If you get re-entry (not exit) permit leave and fail to return before it expires (same date as your extension is due) you will only get a visa exempt entry. You have start all over again by getting a new visa and then an extension of stay.

Thanks for that.