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 - $35.30
Lightly Played - $33.50
Moderately Played - $31.80
Heavily Played - $28.20
Damaged - $23.00
NM-Mint Non English - $35.30
Lightly Played Non English - $33.50
Moderately Played Non English - $31.80
Heavily Played Non English - $28.20
Damaged Non English - $23.00
Foil Prices
NM-Mint Foil - $54.60
Lightly Played Foil - $51.90
Moderately Played Foil - $49.20
Heavily Played Foil - $43.70
Damaged Foil - $35.50
NM-Mint Foil Non English - $54.60
Lightly Played Foil Non English - $51.90
Moderately Played Foil Non English - $49.20
Heavily Played Foil Non English - $43.70
Damaged Foil Non English - $35.50