Trading an 04 for an 05

[NJ H2]

I only owe $28,000 so they would be giving me money but I decided against trading last night and here's why.
It seems to me that GM has figured out how to offer employee pricing and keep the payments the same as they were before! Correct me if I'm wrong but even before employee pricing the monthly payments were the same as they are today, around mid to upper 700's.
For every $1000. down you can take off aprox $30.00 from your mthly payment. So if GM is taking $8000 off the price that should = $240. in payments. That means that if they are offering me the 05 at $775. a month now then before employee pricing it would have been $775. + $240. totaling $1015.00 A MONTH!!! and I don't think anyone has paid that for an H2!!
Something is just not adding up!