Is there a name for the bias of comparing numbers on a relative scale?
Here are a few examples.
The car salesman sells you a \$900 navigation system as an up-sell to a \$30,000 car. It doesn't seem like that much because it 900 is a relatively small percentage of 30000. And let's say a top quality system installed, away from the dealership is \$700; a difference of \$200.
What causes us to think \$200 isn't that much?
But if shopping in a store where the top priced GPS was \$700 and all the others are priced around \$500, now \$200 seems too much.
Or how about a homeowner trying to sell a house for \$200,000 when a potential buyer bids at \$185,000 because of water damage in one room. The seller accepts even though the cost to repair the damage might be only \$10000. The \$5000 doesn't seem like that big of a loss for the hassle of having to do the repair, but in a lot of other circumstances (like selling a car) it's a deal breaker.
Another. Take a trip to a neighboring town and you might go a mile or two out of your way to see an attraction you just discovered. Take a trip across the country and you might visit a whole other state, hundreds of miles out of your way.
I know that anchoring bias can cause you to, for instance, perceive a price as being lower because of false higher price. But is it the same as this relative scaling bias? Or is this called something else altogether?