Cost is a moot point, a lot of other countries switched... including the UK.
The only way you can introduce a new measurement system, is in a phased approach, which also greatly reduces the cost.
For instance, starting to provide all those tools with metric units alongside the imperial ones.
As for american standards vs imperial... I always thought 'american standard' was imperial, but with the u's removed from nearly every word 
PS: not so much an angry debate I reckon, than a serious discussion.
You shouldn't feel offended, you're entitled to your own opinion anyways 