Cheapest priced copy (Future Sight): $0.35 at Card Kingdom, near mint, their price list as of .
Imperiosaur 
Creature — Dinosaur · 5/5 · Uncommon · Future Sight · #145
Spend only mana produced by basic lands to cast this spell.
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
3 printings · $0.35 to $1.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Future Sight | 145 | Uncommon | $0.35 | $1.49 |
| Modern Masters | 148 | Common | $0.35 | $0.49 |
| Time Spiral Remastered | 211 | Uncommon | $0.35 | $0.99 |
3 rulings from Wizards of the Coast
- 19 March 2021An effect that allows you to spend mana as though it were mana of any type to cast Imperiosaur won't allow you to spend mana from a source other than a basic land to cast it.
- 19 March 2021If a triggered mana ability produces mana when a basic land is tapped for mana, that additional mana is produced by the source of the triggered mana ability, not by that basic land.
- 19 March 2021If a basic land gains a mana ability, mana produced with that ability can be spent to cast Imperiosaur.