Pittsburgh will become more expensive as more people move here (already happening)
Please explain where you're getting the idea from that people are moving to Pittsburgh. I don't live in Pittsburgh anymore and only visit family there occasionally, but here are the census numbers since 1950.
1950: 676k
1960: 604k
1970: 520k
1980: 423k
1990: 369k
2000: 334k
2010: 305,704 (Wikipedia)
The 2013 estimate is 305,841 (Wikipedia). The 2014 population is 305,412 (PPG). If people have indeed been moving to Pittsburgh in the past 5 years, it looks like they're simply displacing people on their way out.