There are several factors that can affect the price of a used CNC machine, including:

1. Age and condition: The age and condition of the machine will have a significant impact on its price. A well-maintained machine that is in good working condition will be more expensive than one that is older or in poor condition.
2. Brand and model: The brand and model of the machine can also play a role in determining its price. Popular and well-known brands will typically command a higher price than lesser-known brands.
3. Features and capabilities: The features and capabilities of the machine will also affect its price. A machine with more advanced features and capabilities will be more expensive than one with fewer features.
4. Location: Location also plays a role in determining the price of a used CNC machine. Machines located in regions with higher costs of living or higher demand for CNC machines will typically be more expensive.
5. Market trends: The demand and supply also affects the pricing, if the market is flooded with similar machines, it would be harder to sell at a higher price, and vice versa.
6. The time since last maintenance, any upgrades or retrofits, and any warranties or guarantees on the machine can also influence the price.

It’s important to research and compare prices of similar machines to get a better understanding of the market and what a fair price for a used CNC machine would be.