Where can I buy a cheap Factory Unlocked iPhone 4S/5 other than ebay or amazon?

Looking to buy a Factory Unlocked iPhone 4S/5 but ebay and amazon are too expensive, looking for around $300

Craigslist would be your next option - a private party transaction.

I don't think you'll find any iPhone 4S or 5 brand new for around $300. If you're OK with used, then you can find iPhone 4S in good condition for that budget. If you want iPhone 5 in good condition, it will be around $500. Check online for sellers selling them at reasonable price.

Yes! Factory unlocked iPhones are too expensive.So, i would suggest you to buy a locked iPhone 4s/5 for low cost and unlock it by using free instructions/get Remote unlocking service from any of the service providers like
http://www.theunlockspot.com/apple/rs10wp8/ to unlock your iPhone 4s/5.