How much are MP's worth ? : The Nag

In earlier post I tried to think of a possible renumeration for our representative.
I do realize that saying that paying to representative on the scale of CEOs is a far fetched idea and even western democracy do not pay this much however I was trying to find entirely financial incentive for politicians and this is the nag.

First let's assume that country doen't fear any external threat and no, leadership is not about being alpha male or female only.

Is there a incentive or a cause or a reason for a career in politician in a society based on free market ?

I use free market for the reason that a society which is based on socialist ethos. altruism and duty will define the cause and compelling reasons for politicians.
It is a different matter that socialism has failed and justfiably so , as it seeks to destroy individual will for collective position. Altruism while a pleasant sounding word, is not only contrary to human nature, but it is a trangression of the human spirit, of the person who gives because he does it out of obligation which is out of place , and of the person who takes , because he no longer remains independent.

However consider a society based on ethos of free - market and self interest , what is the incentive ? IMO not much . Politics is so much full of hassle that only renumeration is not good enough for entering politics or even if conceded that such is posssible I think it will result in increasing bureaucratization of politics, which I think goes against the grain of conventional politics. From some science fiction I read long this indeed was predicted , a nominal leader , in essence a carrer bureaucrat being at helm of affairs.

This is I think libertarian position, and if it is true then in long term this question will be solved.
However , if it is not so and political structures do have a meaning even in free societies , what is the motive ? This is what perplexes me ? I hope I will get an answer.