I'm personally a mini / tiny board collector and I do not see any reason not to run most of the logic / IO on the board instead having a need of external computer that uses the target device as a puppet.
Let's start with the mini boards. Some weeks ago, I received my new Raspberry Pi 2 with 4 cores in it's new cute box. Pi is one of the lots of other mini boards I have been buying last years. I do really appreciate the mini boards. They control my home media, central backup and I use them to develop apps on every possible screen and environment.
I have to admit that the new Pi 2 has an amazing performance comparing to similar price boards (with a similar level of stability!). It didn't took much time compiling whole JXcore right from the beginning and I'm able to run my media server node.js app multi-threaded thanks to JXcore's multi-tasking capabilities and Pi 2's quad cores. I've to tell that it works really fast!
Raspberry Pi 2 cost me around 35-40 USD including the box, adapter etc. (no battery included) I feel like it's a reasonable price knowing the market range nowadays. However, smart phones are also entering into the same price range with the mini boards and they do offer even more features. Most of the time, you don't even need to buy a smart phone to develop something though. Almost every single person around has a smart phone in their pockets, and probably a year or two old at their home. Even more, you can find a basic smart phone for 43 USD. It has a camera, touch screen, battery and more. There you have a fully featured IoT starter unit for a very small price.
Intel's Edison brought lots of horse-power into tiny board concept. This horse power is more than enough to run JXcore entirely. Hopefully they will start advertising their horse power instead old school puppeting approaches.