When I was in college in the mid 2000s my senior project needed a single board computer. We spent $500 on a small PC104 board with a 100MHz National Instruments Geode (x86 compatible) process. That didn't include any RAM or storage. I really wish the Raspberry PI would have been available back then. Especially the Raspberry PI ecosystem, makes interfacing with stuff so much easier. We interfaced a small LCD I found at a surplus shop and it took us weeks to get it working. No you can buy a touch screen LCD for $30 and there are libraries to get it working in about 20 minutes.