Turbo Marmoratus - Help Identify

[dene]

I purchased these two shells at a yard sale for $4 each.  I thought they would look nice in my daughter's ocean-theme bathroom.  After looking them up on the internet, however, I'm wondering if I should risk placing them in a 3 year old's bathroom.  Are these Turbo Marmoratus shells, and are they selling for approx $70 each for 5 inch shells?  

<a href="http://stone-pathway.com/images/Others/shells-0002.JPG" target="_blank"><!-- m --><a class="postlink" href="http://stone-pathway.com/images/Others/shells-0002.JPG">http://stone-pathway.com/images/Others/shells-0002.JPG</a><!-- m --></a>