As long as The Aetherspark is attached to a creature, The Aetherspark can't be attacked and has "Whenever equipped creature deals combat damage during your turn, put that many loyalty counters on The Aetherspark."
[+1]: Attach The Aetherspark to up to one target creature you control. Put a +1/+1 counter on that creature.
NM-Mint - $20.80
Lightly Played - $19.70
Moderately Played - $18.70
Heavily Played - $16.60
Damaged - $13.50
NM-Mint Non English - $20.80
Lightly Played Non English - $19.70
Moderately Played Non English - $18.70
Heavily Played Non English - $16.60
Damaged Non English - $13.50
Foil Prices
NM-Mint Foil - $26.30
Lightly Played Foil - $25.00
Moderately Played Foil - $23.70
Heavily Played Foil - $21.00
Damaged Foil - $17.10
NM-Mint Foil Non English - $26.30
Lightly Played Foil Non English - $25.00
Moderately Played Foil Non English - $23.70
Heavily Played Foil Non English - $21.00
Damaged Foil Non English - $17.10