You asked specifically for the "cheapest" way and I'm going to do you one better and make it simpler.
If the distance isn't too great, I'd get what's referred to as a "DAC (Direct Attached Copper)" or sometimes called a TwinAx cable, this is a copper cable with an SFP+ transceiver built in to both ends. They're pretty cheap, and easy to replace. "Passive" style won't go as far as "active" style ones.
Here's an example: http://www.monoprice.com/product?p_id=12053
Past that, you could alternatively get 10Gb-SR transceivers for both ends, and run multi-mode fiber between them and it should work just fine. You do not HAVE to use "Juniper" transceivers, but you'll definitely want to get ones that are "compatible" with your hardware, they can be quite finicky. Furthermore, by going non-OEM, support is not required to help you in some cases.