Average cost is gonna be about $100 for the board. Oh, did I mention you'll need another $80 for the programmer? It only runs on Windows XP, by the way. Closed source custom USB driver that no one understands. Wine chokes out, so no running it on Mac or Linux. PS: The programmer was the "student edition". You'll only be able to program their low end series of chips, and hardware debugging is disabled.
I forgot to mention. You're limited to the free assembler / IDE, that only allows you to use 4k of space. If you want to use any more, you need to purchase a license for $250. And by "integrated", I mean no using your own makefiles or editors.
There's no "stack overflow" style community, either. Your support is limited to poorly written app notes behind a crumby web portal.
And then the Arduino came out. $20 gives you the board, and programmer. No licenses. No drivers. Open documentation. Works with a fork of GCC. Want to use VIM and Makefiles? An Eclipse based IDE? Work on a Mac? Comes with a vibrant community, a repository of examples, and inexpensive addon hardware.
TL;DR - Want your product to die? Force me to use your crumby closed source / "evaluation period" tools from the 90's, lock everything away behind NDA's and web portals, and provide no support community for your product.
Looking at you, FPGA manufacturers. Does your revenue come from selling chips, or selling crap development environments?