I haven't "worked" in Thailand since owning a footwear manufacturing firm last century and I haven't had a day job in years. The Thai consulate has always accepted a copy of a non Thai checking account and the first page of the most recent non Thai brokerage account statement as proof of financial means.
Thai immigration website states you should have proof of financial means. A copy of our joint checking account and a copy of the first page of a brokerage account is more then enough the last few times applying for a type O non immigrant visa based on marriage when applying at a Thai Consulate in the US.
You should also have a letter from your wife stating that you are still married when applying for an non immigrant type O visa based on visiting your Thai wife.
With regard to Lopez Koa's post above and thinking about about wishing in the early days in the 1960's-70's one rarely saw a 500 Baht note and a one hundred Baht note was was met with some dismay by street-food vendors or at the market. We learned to carry a lot of coins including 10 and 25 Satang coins. We were literally weighted down with a pocket of change. The BKK bus was 25 Satang then 50 Satang for many years. Guay teo or chao pad gai was a few Baht per bowl. A " fancy" meal was 100 Baht.$100 USD really bought a lot. Lopez Koa could have lived in BKK nicely for six months on $500 USD and in the up country of sleepy Chiang Mai longer.
In the late 1960's 1USD= 17-18 Baht,late 1970's about 19-20 Baht/USD and early 1980's until the financial crisis in 1997 the Baht was fixed at 25Baht/USD.
At the height of the financial crisis 49-50 Baht/ USD in 1998 and subsequently around 45 Baht/USD for a period of several years early this century. Since then when the USD was weak it bought 26 Baht and when strong 36-37 Baht. Now about 33 Baht 50 Satang per USD.