Yes, installation of extensions is included in the cost however if there is a need to customize an extension, we will do it for an additional customization fee. Your Project Manager will let you about the cost of customization before initiating the project.
If you have ongoing requirement for our services, we would be happy to offer you additional discounts which we usually offer to the web agencies.
We can deliver 1 page PSD to Magento theme conversion in 3 days. There are factors which affect the turnaround time e.g. complexity of the design, required customization, extension integration etc.