According to my research around all major CMS:
- Standard rate custom Logo creation is about USD 500-600 per piece.
- Standard rate custom template is about USD3,000 - USD6,000 per theme depending on complexity required.
- Standard rate for custom Extensions development is by USD 35 per hour. Usually takes about 60 hours for larger ones.
Here is a site that gives the rates I found for MODX CMS (I cannot link to another CMS Site under CoC forum regulations) so here's a screenshot.
Stock templates for Bootstrap are available at Envato's Themeforest as the most reliable ones, and just port it to php-fusion. Recently, I came accross one quite nifty upcoming for stock bootstrap ones called ShapeBootstrap. Just google it up.
What is the average reasonable payoff? The developers that will quote you a USD8-10 is just a beginning to clock you for couple hundreds of hours. By average, ANY developer can do up to 4-5 projects per month. By average salary in USA is roughly about USD100k (Google pays Interface Designer USD113k - Paypal USD93k) per year. So by average calculations - each month pays about USD8,333, and if handling 5 projects, each project must have been USD1,600 minimum per developer. Anything under that, it's a risk factor for either wasting your time with not much production or fresh-grad working for part time.