For comparison, $36,325 in 2007 is just under $44k in today's money. Inflation is a wonderful thing.
If you actually paid $30,000 then you are also comparing out the door price with the new model's MSRP, because that window sticker gives an MSRP of $36,325. $6000 is not a rounding error. 2019+ Silverados will be discounted from MSRP, just like past models.