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.
Near Mint - $28.10
Lightly Played - $25.30
Played - $19.70
Heavily Played - $16.90
Damaged - $14.10
Near Mint Non-English - $28.10
Lightly Played Non-English - $25.30
Played Non-English - $19.70
Heavily Played Non-English - $16.90
Damaged Non-English - $14.10
Foil Prices
Near Mint Foil - $36.80
Lightly Played Foil - $33.10
Played Foil - $25.80
Heavily Played Foil - $22.10
Damaged Foil - $18.40
Near Mint Foil Non-English - $36.80
Lightly Played Foil Non-English - $33.10
Played Foil Non-English - $25.80
Heavily Played Foil Non-English - $22.10
Damaged Foil Non-English - $18.40