Actually Origin tends to charge more for their products than the competition. You can almost always get better value from Xotic PC or the lesser known PowerNotebooks instead.

In terms of raw power, yes. A custom made desktop would likely be twice as powerful as a similarly priced laptop. In your case, you could potentially get a GTX 980 and a 3.4 GHZ quad core CPU (The Intel Xeon E3-1231 v3). That combination should handle high/ultra settings on a 4k monitor easily