Cheapest priced copy (Commander Masters): $0.35 at Card Kingdom, near mint, their price list as of .
Blood Aspirant 
Creature — Satyr Berserker · 1/1 · Uncommon · Jumpstart 2022 · #501
Whenever you sacrifice a permanent, put a +1/+1 counter on this creature.
{1}{R}, {T}, Sacrifice a creature or enchantment: This creature deals 1 damage to target creature. That creature can't block this turn.
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
3 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander Masters | 208 | Common | $0.35 | $0.49 |
| Jumpstart 2022 | 501 | Uncommon | $0.35 | — |
| Theros Beyond Death | 128 | Uncommon | $0.35 | $0.49 |
4 rulings from Wizards of the Coast
- 24 January 2020Blood Aspirant can be sacrificed to pay for the cost of its own last ability.
- 24 January 2020If you sacrifice a permanent as part of casting a spell or activating an ability, Blood Aspirant's first ability will resolve before that spell or ability.
- 24 January 2020Blood Aspirant's first ability is a triggered ability, not an activated ability. It doesn't allow you to sacrifice a permanent whenever you want; rather, you need some other way of sacrificing permanents, such as its second ability.
- 24 January 2020If the target creature is an illegal target by the time Blood Aspirant's last ability tries to resolve, the ability won't resolve. The creature can block as normal. If the target is legal but not dealt damage (most likely because of a prevention effect), it can't block this turn.