There is no requirement regarding length of marriage. However it will depend on your profile and convincing the Consular that you will be returning and not using the visa to circumvent the system. The fee includes a coaching for the interview. Call Ning for full details.
Lots of mis-info here. Call US Visa Experts in BKK for a free consult. They do many CR-1 Spousal visas to the USA for the past 18 years. Talk to Ning, the office manager.
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If you get married in Thailand and have a long term visa (Spousal visa) your wife can apply for the B-2 tourist visa to attend the wedding. It is a difficult visa to achieve, but a good application and supportive evidence will increase your odds of success.
You can use Medicare in Thailand if you go to an emergency room situation. Mainly for accidents, etc. NOT for hospitalization. I'm with ATENA as the Medicare provider. I believe you'd have to pay either 50 or 100 dollar co-pay.