said; I live in Cambodia and I have been back and forth to Thailand:
1) 30 day visa into Cambodia cost $35
2) If you are 50+ in age you can apply for retirement visa into Cambodia. You still get only 30 days at arrival for $35 but you can get multi-entry one year added for around $300. (This means no visa sticker or $35 fee each time you enter)
3) cost of RT PCR test in Cambodia is $130 (yes US dollar)
4) You can get 60+30 tourist visa at the Thai embassy within 2 days and cost $40