Drupal Commerce Caching Modules
You can use 


https://drupal.org/project/commerce_entitycache


It will cache the commerce entities, rather than build them on each request.

While it works ok as is, after the two "Needs review" patches I added to the issue queue:


https://drupal.org/project/issues/commerce_entitycache?categories=All


I'm using it myself without any problems.

As mentioned previously:


https://drupal.org/project/authcache
https://drupal.org/project/commerce_authcache


Also work well with Commerce