Complex sentence: Many third party developers used the V64 in lieu of the PC64 Development Kit sold by Nintendo; the V64 was considered an attractive, low cost alternative to the expensive N64 development machine, which were manufactured by Silicon Graphics at the time.
Split into simpler sentences: Many third party developers used the V64 in lieu of the PC64 Development Kit sold by Nintendo because of its much lower cost. It was considered an attractive, low cost alternative to the expensive N64 development machine, which were manufactured by Silicon Graphics at the time.