It's run by the Virachey National Park Ecotourism Office (banlung) and camping gear, as well as a park ranger and indigenous guide are provided in the cost. Ranger will help you buy food before. I've read it's an incredible hike and takes you to remote and beautiful parts of the park few people go. There are boat trips and home stays involved. The park is very at risk, so our money will be going to a great cause.
The cost is $513 USD. If I can find 2 more people to split the cost I can afford it (but the more I can get the cheaper it is for everyone).
I'm a friendly 26 year old Australian guy and I'm a very relaxed and accommodating hiking companion. If you're fitter than me and want to walk ahead I don't mind, if you're slower, or need to take lots of breaks I don't mind, if you want to talk a lot and get to know each other I welcome that, if you prefer your own company and quiet that's fine too... as you can see I just really want to do this trek, but can't afford $500 on my own.