If the first result looks close but not exact, compare the set symbol, card number, rarity mark, and copyright line before relying on the match
Here are practical tips specific to European buyers
Given people's desire to have a nice version of their Commander, there are several factors as to why a version of a Commander is expensive
Yes, you can absolutely activate a creatures ability before it dies, assuming that you can pay the costs

Avengers: Under Siege Awaken the Honored Dead Bahamut, Warden of Light Bandit's Talent Banishing Light Barrensteppe Siege Bat Colony Bestial Bloodline Bioengineered Future Bitter Chill Bitter Work Blacksmith's Talent Blanchwood Armor Blood Spatter Analysis Blossombind Boggart Mischief Braska's Final Aeon Breaching Dragonstorm Brimstone Roundup Builder's Talent Burden of Proof Buried in the Garden Call the Spirit Dragons Canonized in Blood Caretaker's Talent Case of the Burning Masks Case of the Crimson Pulse Case of the Filched Falcon Case of the Gateway Express Case of the Gorgon's Kiss Case of the Locked Hothouse Case of the Pilfered Proof Case of the Ransacked Lab Case of the Shattered Pact Case of the Stashed Skeleton Case of the Trampled Garden Case of the Uneaten Feast Chalk Outline Charmed Sleep Chorale of the Void Chosen by Valgavoth Clachan Festival Claim the Kingdom Clammy Prowler
If heads, attach a basic Energy card from your discard pile to this Pokmon