Vietnam and Cambodia are really affordable to everyone.
I have found the people to be very friendly in both countries.
I visisted Saigon and did all the side trips (Megkong Delta, Chi Chu tunnels, Cat Tien national Park), Hanoi including the Halong Bay trip and Sapa.
In Cambodia I unfortunately only did Siem Reap with 4 temples of which Angkor Wat is the most famous.
I loved it and would do it again.