I'm doubtful from what you are saying is accurate, link? Additionally, I've worked for Dell (HP uses the same suppliers) and honestly, you may well regret your decision. The lifespan of a MBP due to design will outlive most other notebooks. If you are looking for a solid notebook that will last you 4-5 years and don't want a macbook, Acer would be my next suggestion, or an IBM/Lenovo Thinkpad.
Just to check, I jumped on HP's website and the Envy which is equivalent, base model is $1000, but it also comes with an i5, not an i7. Making that one change, brings the price up by $575 to $1575, to compare with the MBP 15" i7 model. Graphics card is equally comparable.
$1575 to $1800 (1750 w/ school discount) is not a massive difference IMO.
All in all, yes a Mac is "slightly" more expensive, but you have to compare apples to apples. (no pun intended

) Certainly is not $1000 in the difference.