It depends on how big a factor that cost is for you. If you take cost out of the equation, clearly the Encore is superior. You get:

Great quality.
Interchangeable barrels out of the box, available from a variety of vendors.
A great shooter.
Lots of caliber options.
Great looking gun.

If cost is a factor you make sacrifices with NEF:

Hit and miss quality.
Interchangable barrels that must be purchased and fitted at the factory, or purchased (on ebay, etc) and must be fitted by a gun smith.
A great shooter, if you put some time and tweaking into it.
Many caliber options, but no "magnum" calibers.
Pretty plain in the looks department.

I have an NEF .223 and love it. I would like to buy 12 guage slug and turkey barrels for it, and maybe a good rifle barrel for it too, say.30-06, .308, or .270. The S&W .500 barrel also seems like fun!