DB, building a PC is sinchy but there are sometimes issues with certain parts not loading or being recognized or tiny details like you didnt press the RAM in enough that you have to get through. That being said, you could easily pull it off.
This deal not only removes that labor but is also a great price. Even at cost youd spend close to the same money on CPU, GPU, and RAM.
Monitor: I'm not the best at monitor shopping; I always get the best priced Dell IPS I can afford whenever its monitor purchase time.