What sort of money would I need to spend on a PC to play Skyrim on highest settings with maybe a dozen mods incl. ENB etc at above let's say... 50fps?

Anything else I'd need to know?

Thanks in advance.

Laptop or desktop? Desktop, probably $1-1.5k. Laptop, tack on another $500-$1k. Keep in mind that systems NOT built for gaming will have a tendency to run hotter. You can easily push such an "off the shelf" system into early failure by playing intensive games heavily.