There are many ways to say "This is as low as it goes," depending on the context. The phrase is most often used to indicate that you cannot reduce a price, quantity, or level any further.
In a Negotiation (Price)
If you're haggling or negotiating a price, you can use these alternatives to firmly state that you can't go any lower:
"This is my final offer." (Direct and formal)
"I can't go any lower than this." (Clear and straightforward)
"That's the rock-bottom price." (Informal and emphasizes the lowest possible point)
"This is the best I can do." (Polite and suggests you've made your maximum effort)
"I'm at my limit." (Indicates you've reached your maximum flexibility)
For a Quantity or Level
If you're talking about a physical level or a quantity of something, these phrases work well:
"The water level won't drop any further."
"The numbers have hit rock bottom."
"This is the lowest possible setting."
"It has bottomed out." (This is a common idiom, especially for things like stocks or performance metrics)
When you've reached your emotional or physical limit
You can also use the phrase metaphorically to describe a situation where your tolerance or emotional state has reached its lowest point. In these cases, you might say:
"I've hit my limit."
"This is my breaking point."
"I can't sink any lower."
"I've hit rock bottom."