What Evaluate does is to create an in memory order group with one item and with quantity = 1.0m and use the promotion engine to see which promotions can be applied. You can do the same with different quantity. Yes InMemoryOrderGroup is in an internal namespace so remember it might be changed without a major version 

Hi Quan, thanks for responding

How do I pass quantity to the IPromotionEngine.Evaluate method ? Can you please provide a code example

Thanks

When you have an order group you can just call Run, but with this setting 

new PromotionEngineSettings() { ApplyReward = false, RequestedStatuses = requestFulfillmentStatus };

Not ideal that InMemoryOrderGroup is intended for internal use only but seems the only way to preview applicable promotions with quantity conditions

Quan, is there any performance concerns by calling Run for individual SKUs on a listing page to preview discount prices ? 

Thanks

I'm glad you asked. It should not be worse than you run Evaluate, the actual question is if you have any heavy promotion processor. If all of your processors are fast, then it should not be a problem. (still CPU heavy, but not that bad) 

At this stage only using builtin promotions 

Thanks for your help