Cheapest priced copy (March of the Machine): $0.35 at Card Kingdom, near mint, their price list as of .
Botanical Brawler 
Creature — Elemental Warrior · 0/0 · Uncommon · March of the Machine · #220
Trample
This creature enters with two +1/+1 counters on it.
Whenever one or more +1/+1 counters are put on another permanent you control, if it's the first time +1/+1 counters have been put on that permanent this turn, put a +1/+1 counter on this creature.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.35 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| March of the Machine | 220 | Uncommon | $0.35 | $0.49 |
| March of the Machine | 384 | Uncommon | $0.39 | $0.79 |
2 rulings from Wizards of the Coast
- 14 April 2023For each other permanent you control, Botanical Brawler will count +1/+1 counters having been put on that permanent at any time during that turn, even if Botanical Brawler wasn't on the battlefield at that time. For example, if a +1/+1 counter is put on a creature you control, then you cast Botanical Brawler, then another +1/+1 counter is put on that first creature, Botanical Brawler's last ability won't trigger.
- 14 April 2023Whenever another permanent enters the battlefield under your control with one or more +1/+1 counters on it, Botanical Brawler's last ability will trigger.