RadioShack is planning a new iPhone promotion starting tomorrow that will let new or upgrading users get an iPhone 5s at a significant discount. The 16 GB model of Apple’s latest smartphone will be available for $99, down from the usual price of $199 for all customers on AT&T, Sprint, and Verizon.

Customers who bring in a “eligible” iPhone 4s (which usually just means “in pretty good shape”), will also get a $100 credit towards their iPhone 5s purchase, which knocks the price down to a very manageable $0.

The promotion kicks off tomorrow, April 18th and will be available in physical stores or online.We’re not sure how long the promo will run, but it’s certainly not going to be a permanent price change, so jump on this if you’re looking for a great deal on an iPhone 5s.

For more great deals, don’t forget to check out our sister site, 9to5Toys.