[jerf]

Not writing test code is faster the first day.

It's somewhat faster the second day.

It's a bit faster the third day.

It's probably net faster the fourth day, though by now you're developing noticeably more slowly.

It may still be net faster the fifth day.

It's net slower the sixth day, and the delta gets worse from that point on.

And I don't mean "per bug" on that, either. I mean, per project. By the sixth day of the project, you are net slower not writing any test code. And again let me emphasize net; by day six you are already losing overall.

Expecting test code to be written in the same amount of time as normal code is actually eminently reasonable, indeed it's the only sensible way to do it... if you do it right.