My own exp in Saigon is so old that its probably all changed by now. The park close by to the bekpek/budget touristy area PhamNgu Lao (or so) had many interesting guys later in the evening-but NOT what one would say ´cruising´.
Have in general had pretty bad exp. with about all VN guys working in BKK (my favorite haunt) so I decided after a few to pass them by.
From a very recent find-via other site: massage shop promising ´more´: zspa.com.vn. 1 hr msg in basic room quoted @ about 11US$. Tip comes extra-and this was the 1st time I read such a thing: has to be paid to your guy at reception and will be noted in the big book there!
(IN general-in the poorer ASEAN countries, like VN still is, as Camb or Laos), the usual tip for ´everything´ (for those in the know/locally settled) is like 20-25US$, rounded to a neat figure in local money. TH is notably above that, Indonesia a little below, Burma a lot. Now just try to get that in VN that is so extremely bisnis oriented.
When perusing this forum a few hrs ago I saw that Colombia is also on that range.