@RB Coop
I have private insurance and have to pay out of pocket when seeking medical care which has given me an idea of what things cost.
I've never had surgery in Thailand or got stitches but I go to the doc frequently and compared to other countries care is very affordable. I also recently needed to be taken by an ambulance to nearest hospital and got some urgent check and treatment done after an obstacle race injury. The event organizers took care of the bill so I don't know the exact amount but I don't think it was that much judging by the look at the guys who accompanied me and insisted to pay.
Anyhow at international high-end hospital in Bangkok I've payed 20 EUR for expert consultations (orthopedic, ENT, cardiology, dermatology). 30 EUR for X-ray. 90 EUR for ultrasound scan plus surgeon consultation. 28 EUR blood test. Most expensive was a thorough heart check including stress test and loads of other tests for 1200 EUR. I had to drain my clinch ear, total cost 60 EUR. Physiotherapy following a muscle strain was 40 EUR/session. Treatment for the shingles was pretty expensive, medication cost me around 100 EUR. In general, imported medication will be pricey.
But this is at a really expensive hospital and I could've opted for cheaper clinics or cheaper medication. They usually inform you about pricing before you say yes to anything.
When I lived in the EU as EU citizen I managed to get really affordable and great travel insurance for when traveling outside of Europe, around 8 EUR/year. I would go for one of those that will cover emergency care. You might already have insurance if you booked your trip with visa or Mastercard, worth looking into. Depending on location you might need medevac (but it's not like an helicopter will airlift you out of the jungle, you'll still need to find your way to nearest airport). Thailand has excellent hospitals and doctors.
I don't have any stats but my impression is that most common issue for tourists are scooter accidents.