This looks nice. You cannot assume it will also be a street nav device. The software and data for topo maps and routing is very different then for street. I used to have a Magellan crossover. I still think there is a market for one that does both well. On the Magellan it was like having 2 completely different units. Kind of like a dual boot PC that you can boot in either Linux or Windows. Completely different interfaces. Now with flash memory so cheap, everyone should offer the ability to do both. That said $300 for 100k + 24k maps of NA with a 6" touch screen is a VERY reasonable price.
My understanding about this type of fund raiser, is the goal is key. You essentially make a promise to pay. If they don't reach their goal, nobody pays. But if they do reach it, everyone pays and they proceed with development. I do not believe they are required to provide a working product though, so there is some risk.