Hi again Michael (@kenjiobi),
Your 915ce to me is a beauty!
The Jumbo shape went on hiatus this model year (2012). Taylor will have another Jumbo shape, and it will be a different shape/configuration/build than the last.
For the time I've been aware of Taylors and have been shopping and paying attention, I have only come across 2 standard production Jumbo shape models "in the flesh": My 2010 315ce (sapele/spruce), and a 2011 615ce (maple/spruce) that I auditioned and returned. (I played an exotic Custom Jumbo at a "Find Your Fit" event but it was really just to see and touch a Taylor Jumbo for the first time.) The Jumbos have been more elusive to find. Maybe for the fewer production Jumbos made, when a store might get one I could see it selling quickly. I think people that like Jumbos keep a watch out and snap them up when one comes along. I did that with my 315ce.
With regard to your 614ce, this site (UTGF) has a Marketplace/Classified area, you could do a search there for 614ce and see the asking prices people have been posting. There are other guitar forum sites on the Internet, you can look in those Classified areas too.
When I look at used Taylor(s) I always compare it/them to the most current build. For example, when I came across my 2008 614ce (regular production w/ standard amber finish), I saw it had the same build attributes (forward shifted bracing and scarf joint headstock) as a current (2012) 614ce, except the 2008 has the previous generation 9V Taylor ES. And now (for model year 2012) that amber finish that Taylor used as standard on their 614ce for years is a up-charge!
Others here can provide a more thorough description, your 2002 614ce differs from current (2012) build as follows:
1. ?? headstock attachment. Pre-scarf joint (I believe scarf was started in 2007) Taylor used Finger joint attachment. I don't know what build method was done in 2002. I like the scarf joint myself. But a 2002 at the right price and I wouldn't care.
2. Built-in pickup. The 2002 (from your pics) is Pre-Taylor ES, a Fishman perhaps? The debate continues, many people like and prefer Fishman(?) pre-Taylor ES pickup systems, this could be a plus to the right buyer.
3) Bracing. The 2002 is pre-forward shifted internal bracing that Taylor went to approx. Fall 2004 depending on series if I recall. Many people prefer the tone of Taylors pre-forward shifted bracing (in other words, your model).
4) Break-in or "opening up". Your 2002 if it has been played regularly to semi-regularly should have gone through 2 tone changes (as described by Bob Taylor): One that happens sooner and one that happens later (if it happens at all). Now your 2002 may have that extra special secret sauce tone that happens with a well played broken in guitar. You can't get that with a new guitar.
Another attribute is Condition. The more scratch-and-ding free it is the more you should be able to sell it for. My used 2008 has a small ding on the front sound board but under where my arm passes over the top. Also has a small ding on the back. Your can't see them unless you know they are there. That contributed to a lower purchasing price for me. And in my case the dings are desirable because now I can take the guitar out and play it live and not worry about dings so much!
Another attribute is Fret Wear. Are your frets worn and or pitted where a buyer will object? A good setup with fret work will be +/- $100 so either have that done yourself, or price your guitar accordingly and be prepared to come down a bit if the buyer objects.
Another attribute is: Case Condition. A nice original Taylor case is worth more than a beat-up case. I hope the case looks "decent", as sometimes the case makes the sale.
As a buyer I would use the guitar's overall condition, fret wear, and case condition as areas where I would look to attempt to negotiate pricing downward.
What might be the most important attribute: Tone
. If the guitar sounds inspiring to play, especially that first strum first impression, then a buyer might be more inclined to overlook other things.
I hope you do well keeping/selling your Taylors. You could always post your 614ce here in the Marketplace. You have a Taylor audience here that might be looking for exactly the guitar you are selling.