Hello,
Although, i am new on freelancer, I have an extensive experience in developing core PHP/ Wordpress / Joomla / Open Cart / Magento and Prestashop sites.
The price i have quoted is for 3 sites per day. I can install theme and basic content @ $10 for 1 site. It depends on content of site, if content is less i.e. 4-5 pages per site, then can work on 4 sites per day.
Thanks,
Dharmesh Makwana