Alas, my favorite benchmark site has a limited selection of mobile CPUs but look here: http://cpu.userbenchmark.com/Compare.../m4821vsm12071 http://cpu.userbenchmark.com/Compare...m13661vsm12071 the effective difference is 21% and 33% -- exactly as their clock speed would suggest (21% and 36%). So a Celeron 2980U @ 1.6 GHz would be negligibly slower than the i3-4010U @ 1.7 GHz. They are both Haswell cores and the few additional features of the i3 series simply do not translate into real world wins.

Let's do another comparison: http://cpu.userbenchmark.com/Compare.../m4821vsm13386 this time the effective speed difference is 60% because the N2930 is a Bay Trail core.

Let me emphasize again: core technologies matter way, way more than "Pentium", "Celeron" and such labels.

Head up, there's currently a laptop flash-sale (rotating deal-of-the-minute items) going on at Cowboom (returns and refurbs outlet for Best Buy). There's an Toshiba 11.6" Celeron N2840 + 2GB + 32GB Touch Screen netbook that keeps popping up at $120 that, despite being pretty low on power, might be right for some given the price. AC adapter isn't included, so factor another $20 or so for a universal and likely another $10-$30 for an SD card to expand the storage. This is probably the absolute bare minimum of what I'd consider usable for Windows 10, and even then just basic web/email/office... it's pretty much the performance equivalent of a low-end Atom-based tablet in netbook form-factor. If all of the hardware is supported, this might actually be an ideal platform for RemixOS.

There are quite a few Dell Inspiron 11s available from the Dell Outlet right now at 35% off, putting them in the ~$220 range... still pricey for a Celeron N3050 or N2840 machine, but possibly not a terrible choice if you must have the classic netbook form factor.