Why is certain optional equipment worth so much more than other options that might cost the same or more when new?

This is another great example of the law of supply and demand being extremely demonstrable in the used vehicle market. When new, what manufacturers charge for options is largely dependent on the expense to produce the option. When used, the value of options is much more dependent on demand. Diesel engines, for instance, in a 2004 Chevy pick up retailed for about $5,100 and today they are so popular and relatively rare that we add $6200 for the option and that may not be enough. On the other hand in 2004 night vision was a $2,200 option on a Cadillac Deville and we have a $500 add for it, and that may be too much. Ultimately the value of options is determined by consumers. If they demand it and are willing to pay for it, it will have value, and vice versa. VW Jetta diesels (TDIs) cost about $1500 more than a comparable gas engine and today are often worth about $4,000 more. There is a large demand and short supply, and consumers are willing to pay a premium for them. On the other hand, few people care if the Jetta has OnStar, a $700 option, and consequently we have no add for it.  If I were a consumer and the Jetta fit my needs, I’d be standing in line for the new high tech diesel engine version soon to be introduced for sale in this country.