How does Buddhist (supra-mundane) Happiness differ from ‘mundane’ happiness? The happiness that can be found within our day to day life has to be sacrificed in the form of sense-restraint if one becomes a disciple of the Buddha. Our happiness’s ranging from the mundane to the supra-mundane, ranging from success, good fortune all the way up to skill in meditation, wisdom and Enlightenment comes at a price. So my question to you is, “What is the price?” Only if we can identify this, will we be able to create the proper foundation for us to succeed in treading the path.
Here is an extract from Me and Mine: Selected Essays of Bhikkhu Buddhadasa:

An equally close connection pertains between looking within and true &quot;happiness.&quot; In the Buddhist texts there are two kinds of happiness. One of these is found in home life, called gehanissitasukka, the kind of happiness that derives from being a householder and raising a family. Contrasted with outward happiness is nekkhammanissitasukka, literally the &quot;happiness that comes from forsaking home life.&quot; The reference is to a mental forsaking, a state of mind in which there is no longer the idea of &quot;my home.&quot; This kind of happiness comes from looking within, observing things according to the dhamma.
The happiness of home life is called lokiya sukha or worldly happiness; and the happiness that goes beyond home life is called lokuttara sukkha or transcendent happiness. It all depends on the state of mind. If a person's mind is worldly, he can stay in a monastery or in the forest but will attain nothing more than the happiness of home life. Solitude in a monastery or any other place cannot guarantee lokuttara sukha. This happiness depends on the ability to look within.
No matter where we are, we have the power to transcend a preoccupation with the world, above and beyond the &quot;home&quot;, simply by looking within. There is a large, guarantee return. Without any outlay of capital we obtain this special happiness which appreciates continuously. As the Buddha said, &quot;Nibbana costs nothing; we pay nothing for it.&quot; All we have to do is &quot;throw away&quot;. If we will just throw everything away then we will get nibbana. This means simply having a mind high enough not to get stuck in the world. That is all there is to it. We throw away the world completely and get nibbana in return. We do not have to invest anything. We only have to be empty, to live rightly, and nibanna will come of itself.

Note:

It says that the Buddha says, &quot;Nibbana costs nothing; we pay nothing for it.&quot; -- I don't know which sutta the venerable is paraphrasing when he says that, but that agrees with Dhammadhatu's answer
Being required to &quot;throw everything away&quot; everything might seem like a cost; on the other hand the one example of what you have to throw away is &quot;the idea of 'my home'&quot; -- if all it costs you is an idea (e.g. &quot;ego&quot;) that's maybe not a really tangible cost.
You wrote &quot;supra-mundane&quot; in the OP and I'm pretty sure that the Pali word for that is lokuttara (similarly, sukha is &quot;happiness&quot;).

Lokuttara is used to refer to the four paths and four path-fruitions.
Apparently its etymology is,

Loka + Uttara = Lokuttara. Here Loka, means the five aggregates. Uttara means above, beyond or that which transcends. It is the supra mundane consciousness that enables one to transcend this world of mind body.

That meaning (i.e. &quot;above&quot;) might be why Bhikkhu Buddhadasa wrote, &quot;having a mind high enough not to get stuck in the world&quot;.
Bikkhu Buddhadasa expands on that in this lecture:

Even an old man who can hardly move about and must remain at home all the time, if he knows Dhamma at this level, while still living in the home, may attain the happiness that comes from forsaking the home life. This is because the term &quot;forsaking the home life&quot; refers to a mental forsaking to a state in which the mind transcends worldliness and goes beyond it. A person who is living at home may experience the happiness that comes from the home life. Or, he may experience the happiness that comes from forsaking the home life, provided he is capable of looking within using the technique and method of Dhamma.

Reading that, maybe you could say that another &quot;cost&quot; (or maybe &quot;prerequisite&quot;) is &quot;knowing Dhamma&quot;: i.e. time, effort, attention required to learn and to practice the Dhamma.

This answer doesn't directly address the sentence, &quot;The happiness that can be found within our day to day life has to be sacrificed in the form of sense-restraint if one becomes a disciple of the Buddha&quot; in the OP, but it does try to illuminate what was asked about i.e. supra-mundane happiness and cost.