When the researcher has a small budget, and need microchannels of large feature size and a simple mold fabrication is enough for PDMS chip then it could be logical to found an inexpensive setup for own devices. When the researcher has already a well equipped facility and well-educated staff, it makes sense to prototype own PDMS microfluidic devices.
The researcher needs a fabrication partner as uFluidic
When the researcher have an adequate budget but need to conduct a serious microfluidic project, it is better to purchase from a professional custom microfluidic PDMS devices production company. It is also reasonable to outsource service for several replica of repeatable and reliable PDMS chips for the academic or start-up projects.