How much I should sell my iPhone 4 with accessories for?

I have an iPhone 4 that I'm selling as I just got the 5. It is used but in good condition except the battery is now faulty but I'm purchasing a replacement for it, although not fixing it myself as I wouldn't feel comfortable doing it because I'm terrible with technology.

This is exactly what I'm selling:
iPhone 4 - used in good condition
Charger (with the USB)
Charger case
3 standard plastic & silicon cases
Simple docking station
Replacement battery with the tools to replace it

I'm selling it to my boyfriend who will know what he's doing with the battery replacement. I want to know how much this is worth so I can decide on my own price that's appropriate for someone close to me. Obviously I don't wanna just give it away but I don't want to overcharge him and I have no idea how much these things are worth!

Answers are much appreciated, thanks.

So your phone is missing it's original battery cuz it is not good anymore… Maybe 300 and something… But that's just my guess