There is the old adage - penny wise and pound foolish. Many expats and visitors to Thailand look for law firms in Bangkok, Pattaya and even Phuket and Samui for law firms on the cheap. They want to save a buck here and there without thinking of the possibility that something can and will go wrong. Ask yourself first and foremost why is it cheap. Where are the cuts being made in order to save? Very possibly the person you speak to is not an attorney and never has even been to a law school. Yes, on the internet everything is possible. A high school dropout could portray himself as an attorney much like a boiler room operator wants you to believe that he is a stockbroker.
There are no hard and fast rules for finding a Bangkok law firm or Bangkok lawyer. The best advice is to check the Thai forums and ask around on these forums. Always ask - it could save you later.
Buying a house in Isaan? Do you know you cant own the land in your name and that your wife will more likely than not get the land and house in a divorce? What is the truth and how do you protect yourself - a prenup?
Many mistakes are made and millions are lost every month by foreigners who believe they know the law or that Nui or Lek will never sell the house and evict them. How many bars in Pattaya are lost when the relationships break down. This happens all the time and YOU are not unique. Get yourself protected and get proper legal advice before you sign a marriage registration certificate, lease or property purchase agreement.