Price you paid in showproduct.php
I see no special reason why the field "price you paid" is left out at the bottom of showproduct.php . It has all the other fields.
Most users use this Add your reviews section instead of clicking over to reviews.php and will initially not add a price.
I receive questions about this from my site members who later when they realize that there actually is an option for this, want to add it to their review. I have to ask them to edit their review to add the price which give them the opportunity to use review.php.
I did a search about this topic on this forum and a couple of others have asked about this and both received a simple "no, this field is not there".
I recommend strongly that this field is added to showproduct.php.
If there is a special reason why it cannot be added, I recommend to remove the Add your review section and replace it with a link to review.php like the link on top of the showproduct.php. This way, we can provide a consistent review with all options in place.