I visited Vietnam four times last year from Hanoi to Ho Chi Minh city and nearly all major cities and tourist areas in-between. I met many good looking guys for free, two have become good friends and the guys I did pay were asking 400 - 600K Dong. I like Twinks and they were of the highest quality for their looks and for sex IMHO. They will often quote in $US and one guy asked for $US100 and I was happy to reject his offer. They will try you on for a high price but there are many willing guys happy for return visits if you are fair with them.