Is the Philly scene like NYC, where it seems to be either biglaw or $50,000?
Small PI firms start around 43k/year, which is on par with the DA and PD's offices. If you are willing to bill 2200-2400 hours/year (approx 70 hrs/week in office) you can get a gutter ID job at a midsize firm for 60k.
If you're top 10% at Villanova and make law review, you'll have a decent shot at biglaw. Otherwise, be prepared to work for 45-50k/year. A lot of 'Nova grads end up in doc review because they can't pay their bills otherwise.