Jagwire is very good, but no longer significantly cheaper than Shimano. I buy whichever is on sale via Amazon or other seller. The single bike kits are handy but if you plan to redo more than one bike it may be more cost effective to buy the bulk rolls of cable housing (20' or so, I think).

Last year I got some blue brake cable housing from SunLite, for something like $10 for a bulk roll. It's listed as compressionless, but in reality it needs to be used regularly for a few weeks before it stops compressing. It takes a set, effectively shortening the cable housing, so I needed to adjust the cable tension about once a week for the first month. Now it works fine. But it was a PITA for a few weeks. I got what I paid for.

To be honest, even Shimano's cheapest entry level cable and housing are pretty darned good. They don't look like much but they work very well. When trial fitting a new handlebar, stem, levers, etc., I'll usually start with the entry level Shimano cables/housings that came with a set of cheap RevoShift grip shifters or SunRace SLM10 friction thumb shifters. Even Shimano's cheapest cable housing is fully functional and doesn't take a set and need to be readjusted like the cheap SunLite stuff.

That low end Shimano housing is what I have on my Trek 5900 right now, after installing MicroShift brifters a couple of months ago. After I finally settle on a handlebar/stem combo with reach that doesn't kill my neck and shoulders, I'll install some better looking cable/housing. Probably hi-vis yellow from Jagwire or Shimano. It clashes nicely with the purple frame.

However the entry level Shimano cable sets usually include galvanized steel cable, which will oxidize after a few years depending on weather/humidity. It'll make the brakes and shifting feel a bit sluggish.

I also got a bunch of cheap Blue Sunshine stainless cables, shifters and brakes, on Amazon last year. They don't seem to stretch much and usually need only one retensioning after a week or two.