The value you are trying to inject is a simple hard-coded value. For constant values like hard-coded values and configuration values, just use the Register
method:
var uri = new Uri("http://localhost:60001/AuctionDataService.svc/");
container.Register<IAuctionContext>(() => new AuctionContext(uri));
The Register
method ensures a new instance is returned each time.
When it comes to injecting values that could change during the course of the application, please read this article about injecting runtime data.