How much would a BMW lease be?

I am planning on leasing a BMW that is worth around $40,000. I am going to put 5000 dollars down and need to lease it for 48 months. The website calculated the lease payment around $450. Is this the price that i will have to pay? How low could i negotiate it? I am looking for estimates, I know it is hard to know the exact number without the details.|||I got my 2010 528xi. I requested a finance quote and a lease quote. I went with finance because I already have another car for lease so financing will be a better choice. Well for the lease, my 528 was about $1.2k for 58 or so months (interest not included). You can negotiate (which I did). No that is not the price you have to pay, an rough estimate right now you can lower is maybe $100 less ($350) Maybe you can go as far as $300, but I cannot guarantee. But I know for a fact $350 will work.