popeyetyty :
High end motherboards allow the PCIE lane to take more wattage than recommended with less threats, it also allows for a more reliable MOBO, as in it will turn off system if something bad is going on and will do so more efficiently, i had a mobo that would not automatically turn itself off and that is bad, also better OC potential, SLI Support, Better CPU support/GPU support as well.
You need to make sure you actually know what you are talking about before trying to help. The majority of this is wrong. High end mobos do not put more wattage through pcie. There are a few mobos that have a separate pcie power cable directly on the mobo but this is for stability not more power. Going out of pcie spec is bad for the mobo and gpu. Gpus will also not take more from the mobo anyways and as we saw recently with the rx 480 issue, it's software controlled and a serious matter when you go out of spec. Standards exist for a reason.
There is no efficient way of turning off a pc from a hardware issue. In either case, things become unstable and crash so your pc still goes off. Temps may get higher on lower end mobos which may not vrm heatsinks but you still have a safety temp and/or causes instability. If the mobo is so poor quality that temp safeties don't work then they are probably out of business already. We don't see that issue nowadays.
Better cpu/gpu support? B150 and z170 or any consumer lga 1151 chipset would support all the same cpus and gpus. There is no 1151 consumer cpu that is somehow different and wouldn't be compatible and neither are gpus since it's the same pcie versions. There are those few oem mobos that are less wattaage and less than 75w through pcie but you won't see that in the aftermarket.
You can find quality mobos that are cheap but the big reason is features.