Unfortunately, Boost does not offer payment plans for their devices.
Boost Mobile had a $150 off promotion for the iPhone 5s that ended January 25. Boost Mobile also does not offer payment plans when you purchase a new device, making it really expensive.
Even though it won't be on the market that much longer, here are all of the Phone 5s options up for comparison on our website.
Click here to Compare all iPhone 5s
From these results, here are some plans that might be beneficial to you. These carriers DO offer monthly payment plans for an iPhone 5s. From these results, you will be able to compare data inclusions, minutes/messages and prices to chose your best option.
I believe your next cheapest option would be to purchase an iPhone 6. Here are all of the available options up for comparison on our website.
Click here to Compare iPhone 6 options
Remember choosing different ways to pay like through monthly installments, early upgrade or lease will make that expensive upfront cost really affordable by splitting the cost into a 24-month payment plan. You can select different ways to pay, under the picture of the device, between the list of carriers and the image.