Hello ,
My understanding about the project is that you are looking for Migrate magento 2.2 website into nop-commerce. We have a large team of magento developer experience working on Magento 1.9.x and 2.0 and can help you better. Please allow me to have a close discussion over chat so that can get your points exactly and then only after getting 100% understanding over the project scope will let you know the revised cost and time frame. Waiting for your positive input.
Regards,
Prasoon Singh