@Jason *********
Google broken today or what? :O
From the thai consulate in Savannakhet the year-long, multi-entry Non-O visa is 5000baht, from the one in Ho Chi Minh City it's 200 US Dollars.
You show the original rose bordered marriage certificate (Kor Ror 3)
you need copies of:
data page of your passport
visa and entry stamp
front&back of the original marriage certificate
front&back of your thai wife's i/d card
thai wife's house book listing.
filled out application and passport sized photo(s)
fee
** NOTE - in HCMC you also need a hand written letter from your wife to the consulate asking that they issue you the visa.