How do you value your card collection?

Since the very first sports card was made back in 1869 up until 1984 with the very first Dr. James Beckett Monthly Price Guide what was used as the value of sports cards? I have asked several older collectors this question as it comes up each time I meet someone at a card show or run into them in the local hobby shop. 100% of the time the answer is the same, the love of that team or player had the highest value in the eyes of that collector.
Now with the internet you can find a different price for a card in multiple places. You have eBay listings, store websites, Beckett Online pricing, Collector forums, and auction warehouses. Along with the internet you have your local hobby shops and sports card shows with their own pricing as well.
Most people use Beckett for their value of a card. You will see advertisements within an eBay auction for "50% less than listed in Beckett monthly", the same can be said for Local card shops and dealers at card shows. Does the Beckett Monthly Price Guide hold the key to the value of your cards? It does in one way or another as most people will refer to the guide when making trades within collecting forums or with dealers/hobby shops. This has been the main reference for decades within the hobby, heck before the internet was born it was the only source to the card collecting world.

So the question still remains out to you; How do you value your collection? Are you more of the Pre-1984 type that values their collection with a more personal touch of nostalgia? Are you the type take the price in the guide to hold true and would not budge on it even for a friend? Or do you work with the market at that time and ride the trends? There are many ways to value your collection or cards you are looking to sell or flip to make some money towards the next product coming out.
The way I look at my personal collection is different from what I view my Flippers. For me I have a couple of personal collections on the go. I have a "Rainbow", Player, Team and set collection in the works right now. How I personally value these is a little different for each. For example the "Rainbow" collection is a player for the 2011 Topps Baseball set. Since it has been out for over a year I know it will be tough to find some of the parallels. Knowing this if I see one of those lower numbered cards I will take it for a higher price than I would have when the set was released. The Player collection is for a minor leaguer in baseball. Since he has very little cards in the community I am more laid back about getting some of them because I know once he's called up people will put them on forums or eBay to sell as he would be "trending" the market at that time. And as for the Team and set collections, there is no rush on grabbing those cards. Both are in plentiful amounts as lots or singles that there isn't a real rush to obtain them. Plus it is a little different when you are targeting on one certain player or "Rainbow" card as they are limited to what you can get after a product has been released for a while and even sometimes at the release with certain lower numbered parallels.
With Flippers I have found you can go one of two ways. First and most popular is get it out there when they are first released and populate the community. This creates an instant value for your card before pricing is even wet on the paper. Collectors have no idea what value a card has other than what the last one sold for. This can work for collectors but can also back fire. I have seen int he past when the community is flooded with new released cards before pricing is out int he market place and seen some cards go for a lot less than what the pricing is listing them at as well as auction end prices a month after a release. There are many variables to make this happen, but if you are a regular Flipper of cards you need to be on your game to make it work. Myself, I watch the trends of the market. Just as the stock market moves during a day the same happens within the sports card collecting world. Our market tends to have very high peaks when products are first released or if a player is on an MVP or championship run. other than those defining moments the market tends to even out a couple of weeks or a month after a new product is released. This is when I find the true value for cards. People aren't in panic mode to find those rare cards or complete their sets. More volume is out there but the pricing is very close between sellers that you can take your pick.

Looking at my wall of Beckett Price Guides (close to 100) from years past while writing this piece has given me another question to ask; Have you ever gone back and looked at an older Beckett Price Guide to see what a card was listed at near the products release or the prime of that players career? I have numerous times. In fact right now I'm looking at a 1990 July issue of Baseball Monthly. Looking back at that published magazine brings back memories. Lets give a couple of decent comparisons from that guide to this months guide (August 2012). The famous 1952 Topps Mickey Mantle is listed for $7000.00 (High Column) as compared to this months guide at $30,000. 1988 Score Traded Mark Grace is listed at $35.00 compared to $8.00 in 2012. Just two examples of cards that both have had some events in years past to change the values on them both. But as a collector of either of these cards, do you value the Mantle at or above the $30,000 now that he has past? And do you still value the Mark grace card at the $35.00 value even though you could pick one up for $1.00 currently on eBay?
Collectors will always have a different point of view of their own collections value. This creates more good for the community than bad. It's the ones flipping for huge mark ups when a product goes live that cause an issue sometimes. So don't get bummed that a 2012 Finest Yu Darvish Rookie card was at a "Buy it Now" of $25.00 within the first couple of days of the product being live. The price will go down in the next couple of weeks and settle at the normal average price for that card. Hey it might just be the $25.00 but you never really know right away. To the person who owns it in their own collection whether it be a "Super" collector or baseball card collector, it could be worth much more to them.