Cheapest priced copy (Secrets of Strixhaven Commander): $0.59 at Card Kingdom, near mint, their price list as of .
Brass Infiniscope 
Artifact · Rare · Secrets of Strixhaven Commander · #51
{T}: Add {C}{C}. When you next cast a spell with {X} in its mana cost this turn, you draw a card and gain half X life, rounded down.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
2 printings · $0.59 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Secrets of Strixhaven Commander | 51 | Rare | $0.59 | — |
| Secrets of Strixhaven Commander | 99 | Rare | $0.59 | — |
3 rulings from Wizards of the Coast
- 20 March 2026The value of X in the delayed triggered ability created by Brass Infiniscope's ability is the value of X of the spell you cast as it exists on the stack when that ability resolves. (Usually this will be the same as the value chosen for X when the spell was cast.)
- 20 March 2026The delayed triggered ability created by Brass Infiniscope's ability resolves before the spell that caused it to trigger. It resolves even if that spell is countered or otherwise leaves the stack without resolving. In that case, use the value of X as that spell last existed on the stack to determine the value of X for the delayed triggered ability.
- 20 March 2026You'll only gain half X life no matter how many instances of {X} are in the mana cost of the spell you cast.