Check back frequently to get price scoops from a Magic retailer and single speculator of 19 years!
A fine example was Nightveil Specter. Above is the price data, with a vertical red line at the date I purchased 24 of these cards for $1.99 apiece. I reasoned that these were spiking due to their interaction with devotion, a central mechanic in the then-just-released theros block.
Within 4 weeks, I resold all of them for about $7.00 apiece, a profit of over $100. It looks like they're jumping again, in the past couple days (not as large a jump).
A further use of this blog is to coordinate buy-outs of price-jumping cards. If I buy 24 of card X, because my budget only allows me to spend $50 on that card, but I spread the word about the cards imminent price-jump, further purchases from attentive readers will further decrease the online supply and increase the market price. So obviously, I'll be making my purchases before I post about cards, but it's in my interest to post about them as soon as I buy them.