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 - $53.00
Lightly Played - $47.70
Played - $37.10
Heavily Played - $31.80
Damaged - $26.50
Near Mint Non-English - $53.00
Lightly Played Non-English - $47.70
Played Non-English - $37.10
Heavily Played Non-English - $31.80
Damaged Non-English - $26.50
Foil Prices
Near Mint Foil - $85.60
Lightly Played Foil - $77.10
Played Foil - $59.90
Heavily Played Foil - $51.40
Damaged Foil - $42.80
Near Mint Foil Non-English - $85.60
Lightly Played Foil Non-English - $77.10
Played Foil Non-English - $59.90
Heavily Played Foil Non-English - $51.40
Damaged Foil Non-English - $42.80