If the case is that you want to extend the holiday consumerist spirit somewhat, or even expel some funds before the year ends, then João from The Render Blog may have just the thing for you if you are into Maya, scripting, and creating tools.
The Render Blog has posted a look at creating an interactive tool with the Autodesk Maya C++ API, recompiling code form the devkit to create a python script to create an interactive viewport render tool in Maya, that will let you create region of interest renders from any view.
In the end you will have your own viewport rendering tool and a very strong knowledge of python scripting and maya UI customization
For a mere $25, you get a step by step guide into creating the interactive Maya viewport render tool, with all the source code provided.
The course covers using Visual Studio to compile some Maya C++ API commands, and using python in Maya to do the heavy lifting. João notes that users with little scripting or advanced scripting experience will both be able to follow along, and take aways something from the mini-course.
The guide uses Maya 2014, however should work with any version of Maya from 2011 on. Check out the Maya guide for creating an interactive viewport render here.