Okay, it's deeper explanation time.
Make the initial meeting with Helpful Item Character (HIC) a normal, no restrictions, no auto start event. He'll say his "Oh, wouldn't it be cool if you have this item that only I have?" schpiel, then you turn on a "Talked to HIC for the first time" switch. In a new page on that same event, set the "Talked to HIC for the first time" switch as the precondition, and have him say a little "You can't have the item yet" ditty.
Let's say you find a "rad toaster" somewhere in your travels that HIC really wants. When you open the conveniently placed chest with that item in it, turn off that "Talked to HIC for the first time" switch, turn on a "Got the rad toaster" switch, and put a rad toaster in your inventory.
Next make a parallel process anywhere in HIC's house with the precondition if item "Rad toaster" is held, then carry on with your event. Make him walk to you, give you the item, take away your rad toaster (so it doesn't keep replaying), and walk back.
Last little thing, go into your original HIC, make a new page, and set the precondition if switch "Got the rad toaster" is on, then he'll say something like "How are you enjoying my awesome item that I gave you?"
If that didn't make sense, here are some pictures: