I think you'll find that $225 is a decent price. $250 seems to be the average price. You can google up plenty of charters, but I've used Bob's Trophy Charters with good results. He does cost a bit more at the figure I quoted above. Go to
www.ourdoorsdirectory.com and click on the saltwater forum. This is the Alaska Fishing Forum. You will find info about Homer charters and the folks who use specific charters regularly.
If you're staying in Soldotna, you may want to check charters in Ninilchik/Deep Creek. Homer is approx 70 miles south of Soldotna. Fishing out of Ninilchik will generally get you fishing inside of an hour, depending on what you are looking for. Homer can be somewhat longer. You can probably find some slightly cheaper, as I have seen prices from $215-260ish. You will not find "bargain" charters, except possibly a half day charter in the $105-125 range.
These are normal prices and are not "steep" for Alaska Halibut fishing. If you can swing it, just bite the bullet and enjoy yourself. Also, with 5, you will most likely have the boat to yourself, but since most boats are "6-Packs", there's always the possibility of having a single placed with you. Something to keep in mind.
If you choose to go to Homer, do not leave on the charter without your Homer Halibut Derby ticket. $10 is a small price to pay on the off-chance you catch a HUGE halibut. The possibility exists for a $40K win.
Good luck and make sure you post some pictures and tell us how you did.
Garion33