When my last '11 Sierra got totaled, it had aftermarket rims and tires on it. The insurance company (when it came down to the value of my truck) said that I lowered the value of my truck since I put $2000 rims/tires on it, and took off the stock rims that are apparently worth $1000 each.
So for stock wheels, it should be $4000 for the rims alone.
In reality, you can find a set of rims/tires for about $800-1000 Canadian. That's what I found when selling both sets of mine from my trucks.
For the sidesteps, I've seen them listed for $250, I sold both sets of mine for $200 each.