You'll have to provide the angles on the certification before we could comment on anything, but if you could get an ASET image from the jeweler that would be ideal. What I can tell you now is that EGL has a reputation for grading softly on color and clarity compared to the more reliable labs, so it's possible that GIA would rate your H VVS2 as a I VS1 or worse.
I think a lot of diamond shoppers start off with mentality of wanting a 'good deal' on the price. There are rarely any true good deals for diamonds, everything is priced at an amount for a reason. If a stone is priced low (compared with proven ideal cut stones with the same color/clarity/carat grades), its quite possible that it's because of a bad cut. EGL doesn't do cut grades for princess cuts, if I recall correctly. I do hope I'm worrying for nothing though for your case.
Most PSers would rather a smaller, lower clarity (but still eye clean) diamond that has a superior cut, than a larger higher clarity stone that isn't ideally cut. Cut completely determines the sparkle, which is the whole point of diamonds isn't it?
Is there a return policy on the stone? There have been far too many stories of people coming here after they bought their diamond, and past the return date, only to find that it wasn't the best purchase they could have made.