To transfer from Saigon to Cambodia usually people will take flights, beside you can take busses.
The flight is usually around $165USD minimum and takes fifty minutes or so. It's a monopoly by Vietnam Airlines, so prices aren't going to drop any time soon. By the time you get to the airport, wait for the flight, exit the other end and wait for luggage, you are looking at three and a half hours. The bus costs between $8 and $12 and takes six hours normally, so you are paying $1.02 for each minute of the one hundred and fifty minutes you are saving.
So it depends on your budget and also your heath standard. But during the way from SG to Cambodia, there aren’t many things to see but if you want to experience, it will be a choice.
Some of worth-considering bus providers including Vietnamese firms like Mai Linh, Sapaco or GSG, and also Cambodian providers such as Mekong Express, Capitol Tour and 168 Bus. Buses of Mekong Express also have a tour guide to introduce and assist guests along the trip. Below are some addresses where guests can purchase bus ticket to Cambodia.
* Mekong Express: 275F Pham Ngu Lao Street, Dist.1 – (+84-8) 3 837 3917
* Sapaco Tourist: 500 Nguyen Dinh Chieu Street, Ward 4, Dist.3 – (+84-8) 3 832 2038
* Mai Linh Express: 292 Dinh Bo Linh, Ward 26, Binh Thanh District – (+84-8) 3 929 2929
To have detail information of buss from Sai Gon to Cambodi, you can read more here: http://www.howtogotocambodia.com/bus-to-cambodia/bus-saigon-to-phnom-penh-via-mocbai-bavet-border-/