This week in Magic finance, the biggest gainer was Gruul War Plow, with the artifact doubling up to just over $4. The artifact doesn't really see meaningful play in any format, including Commander, so why the big price spike? As far as I can tell this is mostly the power of never having been reprinted. Gruul War Plow is from Guildpact, a set that released nearly 20 years ago, and somehow has never been reprinted - like anywhere, not the list, not in a Commander precon, no place at all. As a result, the supply is low compared to the size of the current playerbase, which makes it easy for the price to jump even with a relatively small increase in sales. When you are deciding which cards to hold and which to sell, I think that the number of reprints has to be one of the biggest factors. For now, I'd be tempted to sell Gruul War Plow, just because it sees essentially zero play and if it every does get reprinted, it's going to crash back to bulk. 

Meanwhile in Standard, Spyglass Siren doubled up to over $2, which is especially notable because the one-drop is a common and a common being worth over $2 is rare. The card is a true Standard staple, showing up as a four-of in the most played deck in Standard: Dimir Midrange. I'm not sure how actionable any of this really is, but at this point it's at least worth pulling any copies you might have from your Lost Caverns of Ixalan bulk

Finally in Commander Abstergo Entertainment (extended) is on the rise, increasing 77% this week to over $2. The land has increasingly become a staple on Commander Clash thanks to its ability to exile graveyard while also potentially returning a combo piece to your hand. Assuming the card continues to catch on the price could continue to rise. Unlike many Universes Beyond sets where Wizards touts their sales as smashing successes, we haven't heard anything like that about Assassin's Creed, which combined with the known unpopularity of small booster packs (which is how the set was sold) makes me think sales were probably underwhelming, limiting the supply of the card. Toss in the likey difficulty of reprinting cards with non-Magic IPs, and the stage seems to be set for Abstergo Entertainment (extended) to be a long-term riser.