Container for keeping butter/chocolate at 74°F/66°F (23°C/19°C)? Keeping my entire home at 74°F isn’t practical. Is there a device for storing butter and chocolate at a temperature that’s reasonable for use and consumption? Two devices, one to warm in the winter and cool in the summer? 

I’m looking for something with a thermostat that maintains temperature fairly precisely for under $200.
One option might be using either a mini-fridge or wine cooler, and the addition of an external temperature controller, which overrides the internal temperature setting. Combined, the cost would be at or under your $200 target. Here's an example of Johnson Controls Digital Thermostat Control Unit (on Amazon)