They can be interacted with like any other artifact permanent once on the battlefield
If you only have $40 in your Magic budget, which deck should you buy
Only 39 cards were ever awarded and some say as few as 6 are even known to exist
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