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 - $29.00
Lightly Played - $26.10
Played - $20.30
Heavily Played - $17.40
Damaged - $14.50
Near Mint Non-English - $29.00
Lightly Played Non-English - $26.10
Played Non-English - $20.30
Heavily Played Non-English - $17.40
Damaged Non-English - $14.50
Foil Prices
Near Mint Foil - $36.40
Lightly Played Foil - $32.80
Played Foil - $25.50
Heavily Played Foil - $21.90
Damaged Foil - $18.20
Near Mint Foil Non-English - $36.40
Lightly Played Foil Non-English - $32.80
Played Foil Non-English - $25.50
Heavily Played Foil Non-English - $21.90
Damaged Foil Non-English - $18.20