So the discovery kits are a great way to playing around/introduction to the STM32 line. What's the typical BOM look like for a product using these from scratch? I'm pulling datasheets and looking for reference designs now, and they look comparable to AVR in that aspect (Crystal, power regulation, and MCU). From the hobbist perspective, how hard are these to work with? I'm not going to need to deal with BGA or LFN, or 4+ layer boards am I ?