I'd like to know how much of an out-of-the-ordinary increase in value I am getting for an offer on my car. To do so I'd like to know how much my car has depreciated in the timeframe since I bought it (including the current chip-shortage mark up) and compare that to a typical depreciation curve's value. The car is a regular 4 door Acura sedan.
There are websites that will give you the current price range for your car in your area. To know if you are getting a good deal use a number of the sites to get an idea about the current market. Then negotiate from there.
But if you are asking about knowing how much the value has gone up over the last few months based on the chip shortage, then you would have to compare the offered price to what you would have gotten in previous years. To do that you may have to look at the printed copy at your local library. It is also possible that some websites will show you how the price has changed over the years but they may only offer that information if you register at the site or pay for that additional service.
Now if you are trying to get the best price, make sure you separate the sale of the used vehicle from the purchase of the replacement vehicle. Otherwise you can be sure the good deal on the used car will be lost in the worse price for the new car.