The only cards that tend to increase in value are rookie cards of guys who were unknown late round picks and broke out. So like a Mark Stone type of guy.
Otherwise, rookie cards and cards in general almost always peak when they first are released as more people are interested in adding them to their collection. This is especially true for top draft picks.
It is possible that Matthews card could increase in value if he has a prolific career, wins a few Hart/Art Ross/Stanley Cups but the safe thing in the short term to do is to sell now, or at the very least hope the Leafs make the playoffs and sell at that time.
eBay sold listings is a decent indication of what a popular card like Matthews is worth. Right now they look to be selling for around 175-200 Canadian raw. If you have sold on eBay before and are familiar with the process of selling an item, that might be the best and easiest route to go. Just makes sure you ship the card with tracking. It should cost about 10-15 to ship a card with tracking in Canada. If you list on eBay from a marketing standpoint it would be better to list it at 199.99 with free shipping than to list it at 175 with 15 dollars shipping. At the end of the day, you make the exact same amount.
Another route would be to sell it locally on Kijiji/Facebook/Craigslist. You'll probably get a lot of low ballers trying to buy the card off you to flip though. Which there's nothing wrong with in theory, but you shouldn't need a third party to help you sell a card like Matthews when you've already committed to selling it locally. That card should sell itself pretty much as it is one of the most in demand if not the most in demand card on the market right now.
Last option if you don't know how to use eBay and aren't into the idea of going the classified route would be to find your local card shops and see what they'll give you for it. IMO for a card like Matthews, this isn't the smartest move because you shouldn't have to pay someone to sell something that will sell itself. You could literally list the Matthews card slightly underpriced on eBay and have it gone in a day. But if you do want to go this route consider that with eBay+Paypal fees and 10-15 dollars shipping within Canada if you did sell the card for 200 CAD w/free shipping you'll only pocket about 160 after everything. If you choose to sell the card on the lower end at 175 w/free shipping, you're only pocketing around 135. So if you have a shop offering you anything close to that because they know it is a hot card they can sell the same day they buy it, maybe you opt to take it just for the convenience of not having to go the eBay route.
As far as my opinion on selling from packs. I just don't really get it if you're gonna collect. I think if people buy packs, they should keep the hits from them a majority of the time. Because although you had an amazing first pack, the reality is if you spend say 1000 dollars on packs of hockey cards in a year, you'd be very lucky to get 500 worth of cards back. So I don't get the mentality of say spending 1000 on packs, pulling 500 worth of cards, selling those cards, then spending the 500 on more packs where you pull 250 and so on forever. Nor do I get the mentality of buying packs just to trade/sell the cards for cards you want more as singles, I think it makes more sense just to buy singles in the first place since it'll cost less. I think it is fun to buy a pack or box every once and a while the same way someone might buy a lottery ticket every once and a while knowing they aren't getting their money back, but I think relying on packs/boxes to build a collection is misguided.
