Name your price.
ALWAYS keep your cards close to your chest-even with "friends".
Your price is your price.
Try not to think out loud and give out too much information about how many people you are bringing with you, etc. That's your business and the client will find out when you get there. Extra info gives others more wiggle room to whittle you down. Stand your ground, exactly as you did, and never let them see you get upset or offended.
If others are quoting 3 times as much for the same work:
1. There are some greedy buggers out there.
2.The quotes were pulled out of the air (or his ass)
3. Perhaps YOU are undervaluing your own services