Ghee vs. butter in Indian curries It seems that butter is not good for frying things over high heat

because it can burn
However it IS widely used for sauteeing in many cuisines, and works well.
I looked at the cost of butter, which e.g. in the UK is around £6/kg, and ghee is £8/kg.
Although butter is around 18% water, this still makes butter cheaper, and life is easier if you buy one thing rather than two.
The question then is whereas both ghee and butter will impart flavours to a curry, is there a good reason not to use butter? I think ghee is misssing around the 1-2% of milk solids, as well as the water, and obviously if you wanted to deep fry then butter would be unsuitable (you can, I think, deep fry in lard, at around 160C, but butter won't get hot enough without burning). Or is this possibly a cultural issue, in that butter doesn't keep well in hot countries such as India without refrigeration, whereas I guess ghee is probably shelf stable?
Ghee is butter minus the milk solids and water, but it's not the same as clarified butter because it goes through a second phase of the process which browns the solids and imparts flavour to the remaining oil.
Clarified butter, heat until solids separate and settle, strain.
Ghee, heat until solids separate and settle, the increase heat until solids brown, strain. This adds a 'nutty' flavour.
The smoke point for the two is the same, but the flavour is different.
Ghee is not fully shelf-stable. It has a life-span of weeks to months in the fridge. Commercial ghee of course will have a best before date it would be wise to adhere to.
It will not last indefinitely &amp; will (I think) go rancid after long storage… whatever it does chemically, it will certainly ruin a meal if you use it after it's turned. You can't see it, but you can smell it's changed.
BTW, you can get vegetable 'ghee', which is considerably cheaper. Many BIR kitchens use it. It's basically vegetable oil (often palm oil) with 'butter flavour'.