I respect you for putting such an app/tool together for the hobby. I will say that the values today are different from say prior to 2008. At the end of the day, much of it has to do with the supply and demand curve. The values computed today will vary based upon that specific curve.

Again, thanks for putting something together, over time (just like with any app/tool) with good feedback and recommendations it'll only become more effective!

 

Thank you for the kind words of encouragement - to all of those who have given them! And to those who have been more critical too. Criticism really can lead to more innovation.

 

I don't know one yet but well worth looking into. I guess I am becoming an over aged technogeek? LOL

 

You would need at least 30 cars to get a minimum random sample. We probably took a similar statistics course. Then need more samples for each make, model, and option package. In the end, you might have to look at hundreds of cars to create a database. Does your program account for regional differences?

Maybe we can encourage every recent buyer to e-mail sale information to you.

Or even easier, just use:

http://www.nadaguides.com/Classic-Cars

Same method as your program but NADA did all the work.

Hahahahahhaha. Just input my car. That Nada program is smoking crack.

 

NADA for a 1978 Corvette L48, which lists only retail low, retail medium, and retail high:

$10,470 $14,560 $23,050

Here is what mine says:

10% $3,978.93
20% $7,040.69
30% $8,877.74
40% $10,102.44
50% $11,939.50
60% $13,776.56
70% $15,001.26
80% $17,450.67
90% $19,900.07


Frankly, mine sounds right.

NADA is not quite the same as mine since it only gives three (low, medium, high) retail prices. Those are actually probably good prices if you limit yourself to buying from a dealer - which are the ONLY prices NADA gives you. I did a sample of both dealer and private sales. If I knew I'd only buy from a private seller I could have excluded dealers - probably would have lowered the price a bit.

With the calculator you can do what-if scenarios. What if I ONLY buy from a dealer? How much more will that cost me (NADA probably answers that)? What if I get a 1979 instead of a 1978? What if I buy from Indiana instead of Michigan? NADA won't do that for you - and probably overall isn't as accurate since it excludes all private and auction sales. The calculator I put together will.

Anybody buy a 1978 recently? I did. I ranked mine as an 85% and thought I got a good deal at $16,800. It was listed at $17,500, which is just over 80% on my scale.

The calculator says for this search that your sample size is seven. I always say to do 20 even if the calculator says to do fewer. Twenty is really the minimum. There is a formula that will tell you based on the standard deviation how many samples you need - that's what the calculator uses. But you always want at least 20. For some time studies on a plant floor you might need a couple hundred. But car prices don't seem to vary quite as much.

How long does it take to get 20 random prices from the Internet. Takes me maybe ten minutes at the most.

 

Sorry. No offense. But garbage in, garbage out.

 

No offense taken Clubby. I just wish that people who are going to criticize the calculator would take the time to use it first instead of criticizing it without even really knowing what it does.

Goo sampling is absolutely necessary for accurate results, and in the instructions (a word document I send out with the calculator) I talk about that. You can't go only to one site.

Having fiddled with it myself quite a bit I've found that the fastest way to get an accurate result it to take ten values from Craig's List and then ten from the vintage version of Autotrader.com. Make sure you sort Autotrader.com by distance to randomize the prices. Lots of dealers use that site - using Craig's List and Autotrader.com will also let you stay regional.

The Craig's List prices are notably lower - because a much higher percent of sales are private sales and because the overall quality of the cars is lower.

I've also done searches all over trying to be more random than that. Using just Craigslist and Autotrader.com (the vintage version) works just as well.

Only rarely will the calculator tell me I need more than 20 samples - and it has not yet said that with a Corvette I've run through. But apparently other cars don't hold value as well in the lower condition ranges...

I'll update the instructions to annotate that before I send out any more copies.

 

This is a cool little tool and is going to be alot of fun to use. I have only added a few values to see how the overall values at % levels change. Seems to work great. I also opened it on my I phone and found I could view the page but couldnt access it. i searched and played around with free apps. I found that the app "connect" would allow me to grab it from my e-mail after some messing with settings. i can access now but cant save as I cheeped out with free version. So I will end up creating a group of cars on laptop and sending it to phone so I have a proper base to use on the fly. Great job on an excellent application.