I applied for an extension two weeks ago - and received 30 days, even though I just asked for an extra 15 days. Total cost; 1,900THB. If you have money to burn - you could either do a visa run or, (poor man’s option) just pay the overstay fine.
In this case - the process is a simple matter. I filled out the forms, and had insurance within 15 - 20 minutes using the source of info I stated. Within six hours of submitting my application - I had my Thai pass.
Thai pass required. The airport link takes only about 20 minutes to get the Makasan Station. If you’re arriving at a low-traffic time - getting thru customs and out of the airport shouldn’t take more than 40 minutes . Lot’s of factors involved but, 10 hours could be plenty of time to get into the city for a good five, six hours. For cheap insurance - go to the Royal Consulate in Los Angeles’ website - I paid less than 1,000THB for 60 days worth.