If you were about to purchase the Apple iPhone 5S a special promotion is available from Best Buy at present that could save you $150 minimum on the price of the phone, so you’ll pay almost nothing. The iPhone 5S Best Buy special trade-in price offer began yesterday and lasts through today (Saturday) only.

Best Buy has been offering some great device deals lately and this new promo enables customers with a working iPhone 4S or iPhone 5 to trade it in for a Best Buy gift card credit of at least $150 towards the cost of an iPhone 5S. The new handset must be on a two-year contract with AT&T, Verizon or Sprint.

At the same time a special deal on the iPhone 5S 16GB model at Best Buy has brought the price down to $150. This means that effectively you can get an almost-free iPhone 5S from Best Buy for the rest of today when trading in an iPhone 4S or 5, as technically Best Buy will charge you a nominal $1.

This offer is a really good incentive for those thinking of upgrading to the iPhone 5S, and we imagine Verizon will be kept pretty busy until the end of today when the promo expires. The offer is available in-store only and you can see all of the small print at this Best Buy page.

Will you be taking advantage of this very tempting trade-in offer for the iPhone 5S at Best Buy? Let us have your comments.