Let's start with an ironic price chart I posted on Twitter a couple of days ago: Here, we have the Legends printing of the aptly named Greed, which more than doubled in price a couple of days ago (and, compared to a couple of months ago when Greed was around $30, increased about 1,000%)
If your deck's key engine is a 4cmc commander like Kaalia of the Vast, for example, then you will want to run ramp cards that can get her out faster, which means ramp that is between 0-2cmc so you can cast Kaalia on turn 3 or earlier instead of her usual turn 4
They can be interacted with like any other artifact permanent once on the battlefield
Having access to red cards also means you get access to red removal and red card draw effects, which can help to churn through your deck for the answers you need
Only 39 cards were ever awarded and some say as few as 6 are even known to exist
If you only have $40 in your Magic budget, which deck should you buy