Yshtola Rhul Free end steps is an intriguing reward for putting Y'shtola Rhul in the command zone
According to the data on the spreadsheet, at the time, you could buy a foil Grim Monolith for less than $250
They help you produce three colors of mana from one card, though most of them come with downsides like entering tapped or forcing you to return another land to your hand
Sac Lands Fallen Empires introduced the original sac lands, which enter tapped and can tap to add one mana of their respective color, or tap and sacrifice themselves to add two mana instead
Just make sure you've got ramp, protection, and a plan - because once you start swinging, the game might be over
Again, this has a ton of use in Selesnya, and your go-wide deck will capitalize on this ability far better than Golgaris 6/6 bombs