Best hopper for price

[Bigjoe11]

I am looking for an electronic hopper for my 06 spyder electra with eyes. it is supposed to fire at up to 30 bps, and 18 on semi-auto. The other day I was able to shoot ropes with the gravity fed hopper due to the kick back of the gun shaking hte hopper. however, every once in a while it wouldn't fire because the hopper stopped feeding, like that time someone ran across the field and I couldn't shoot becuase my hopper wouldn't feed. I am looking for these things in the hopper:

- The ability to keep up with my gun (I don't use very much ammo, but I fire in quick, very rapid bursts)
- Capacity (I like to not need pod packs because they slow me down too much)
- my #1 thing is BATTERY LIFE. I don't want to worry about messing with the batteries and buying 9 volts, my 9.6 volt spyder rechargable battery is enough.
- Price, I got my electra for $60 and I don't really want a hopper much more expensive than my gun.

thanks for any suggestions about a specific hopper I should buy, and IF YOU'RE SELLING A USED ONE I MIGHT BE INTERESTED.