The gun is probably the finest firearm made. But it might be the best choice for the police academy........
Are you paying for this police academy? Are you already hired?
If the answer is yes to the first and no to the second, I'd hold off on the Sig unless you A. Really want one or B. Have the money to spend on quality :) Nothing against Sigs, I love them. But I had to pay my way through the Academy, then wait 4 months before I was hired on a police department. Money can be tight and the $300 you save by getting a Glock or Springfield might really help out come month five of the academy when you are flat broke.
Now, if you are already hired and a Sig is what you truely want and you are allowed to carry, $800 is reasonable, maybe a bit high. You can probably find the same gun in the $700s if you dig around. $600s if you find a really good deal.
BTW, If you decide to buy from this guy and you are spending $800, tell the retailer to at least throw in a couple hi-caps.