Let me address the appreciation aspect. I am an attentive watcher of violin sales: both at dealers and at auctions. While not a collector, I have four violins, all of them worth more today than when I purchased them. Let me share what insights I can.
You need to consider what you mean by appreciation. Let us for the time being say it's what you can sell the violin for in a six-month period. To be clear, this is not the standard view. Most expensive violins are consigned to a dealer who will make them available for years before they're sold. Right now, for example, if I go to Ifshin Violins, (the largest dealer in the Bay Area and one of the largest west of Mississippi) I see violins for sale that I personally tried out three years ago. If you're willing to have an instrument for sale that long, then my advice won't be terribly helpful.
There are two ways to sell a violin within a six month period: charge little for it to a dealer or, the preferable way, sell it at auction. In both cases, you'll make less than you would if you held out for a high price for years. However, at auction, you can set the minimum and if several buyers like your instrument, a small bidding squabble can quickly bring you unexpected bonus. The auction house will tell you up front what you can expect from a given instrument, so you know going in what appreciation you can expect and whether it's worth your while to sell it there or hold out at a dealer for a higher price..
How then to choose an instrument that you can sell reasonably fast at a profit? I've had this conversation many times with Tarisio and with other violinists who are comfortable moving instruments.
First, buy an instrument that's likely to appreciate. This means at least a $5K instrument (rock bottom is $5K). Older is generally better. And a certificate of authenticity is a big plus. Buyers love knowing that they truly own a violin from a specific maker that was in a specific year.
Second, don't buy it from a dealer. Dealer markups vary from 25% to 100+%. They provide services for that markup, so I'm not saying don't ever use dealers. But rather, don't buy from dealers if appreciation is a key concern. There are two options, which will serve you better: private sales and, again, auctions. In both cases, you can test the instrument. In the latter case, you need to test it on site. But in my case, I went to the site for two successive days and spent 3-4 hours each day with the instrument I wanted. Several times, I had other people play it for me. I was pretty sure come bidding time of the instrument I wanted. With private sales, of course, you can negotiate whatever you want with the seller.
Finally, despite what other folks have posted here, stay away from instruments of living makers. Living makers charge you the retail price. In addition, once you've bought an instrument, every new one they make is competing with yours. Very, very few living makers sell instruments that you could resell in a five years at a profit. They exist, but they are few.
A final tip: If you want to know what an instrument by a given maker can sell for, look at auction results. There are four or five major auction houses and many post their results.
Allow me an example. This article is about a violin by Luciano Sderci (1968). Note that it was badly damaged and repaired. I played this instrument at Johnson Strings, two years ago, which had it for sale for two years at $35K. A viola by the same maker made in the same year in excellent condition sold at auction for $7200 A 1972 violin by Luciano and his father Igino (considered the better maker) was listed for ($12-$15K)[http://tarisio.com/catalogs/tarisio_may_2015_new_york.pdf] [PDF] at auction.
You can do your own research. While, of course, no two instruments are ever exactly the same, you'll see a consistent pattern that auction prices are much, much lower than dealers. That should get you the most likely to appreciate instrument.
I hope this helps in terms of your question of appreciation. Good luck in your quest!