A big part of collecting is recognizing that if you could predict the future of the market enough to really make out by buying toys that rapidly increase in value, we'd ALL be doing it.
There's basically only two ways to make any money from toys:
1) Scalp hot toys on eBay. This will make some board members very, very angry, but you'll have turned a $15 purchase into a $30 eBay sell... minus PayPal fees... minus eBay fees... and then you undercharged for shipping... But hey, you came out of it six dollars ahead for an hour of work!
2) Buy the right one and sell it five years later when everyone wants it. Of course, not all the toys you buy will appreciate unless you're VERY lucky. I have plenty of twenty-year-old MOC toys that I was assured would be worth lots one day. Would you like a red card ugly Leia? I have one that I'll let go for the price I paid for her: $5!
Why do toys appreciate? Supply and demand. Which toys will be in short supply and in big demand in the future? No one knows.
Should you leave your figure in the box? If that makes you happy--as a bonus, you might get to sell it when it has become clutter instead of treasure. If it doesn't make you happy to leave it in the box, the worth of opening the toy--playing with it and posing it--is worth more than the average profit you'll make from it in five years or ten years.
PS: BTW, I also collect comics. My collection is worth $20K in the price-guides. If I could sell the whole thing for 10% of that, I probably would. Consider that.
At least I read the comics. Most of them.