I am hoping that you are enjoying your visit.

If you want cheap, get out of D1. Almost everything is more expensive because that's where the tourists are.

Vietnam is full of oranges, they have green skin, and most places squeeze them fresh. Just ask for "cam vat" at a restaurant or street vendor that sells them. I prefer the fresh sugarcane juice myself since it's pretty cheap. It usually costs me 70 cents in Vietnam and over $5 in the US. Of course expect a mark up since you're a foreigner.

If you go to a fancy coffee shop, then expect fancy prices. Most Vietnamese drink cafe sua da which is Vietnamese ice coffee. The reason why there is so much ice is because you're supposed to let the ice melt to balance the strong coffee taste. Drinking coffee in Vietnam is a slow process, not like how it is in the US where it's about to go everything.

Bars and clubs tend to be dead until around 11 PM, where they start picking up and go to 3 AM. I once stayed out until 6 AM club and bar hopping with strangers, grabbed pho for breakfast, went to bed at 7 AM and got up 2 hours later.

It all depends on what you're looking for in Saigon.