Should he leave university and get a job, and save up some money, so that he can do Hajj?

Firstly:

Hajj is only
obligatory for the one who is can afford it and has the physical strength to
do it, because Allah, may He be exalted, says (interpretation of the
meaning):

“And Hajj
(pilgrimage to Makkah) to the House (Ka‘bah) is a duty that mankind owes to
Allah, those who can afford the expenses (for one’s conveyance, provision
and residence)”

[Aal ‘Imraan
3:97].

For more
information please see the answer to question no. 11534.

If the son is
able to do Hajj, in the sense that he can afford it and has the physical
strength to do it, and he is able to go for Hajj, then he must do that, and
if his parents tell him not to or to delay it, he does not have to obey them
in that regard, because it is obligatory to do Hajj immediately.

Ibn Qudaamah
(may Allah have mercy on him) said:

The father does
not have the right to prevent his son from doing the obligatory Hajj, or to
make him exit his ihram, and the son should not obey his father by
refraining from Hajj, because the Prophet (blessings and peace of Allah be
upon him) said: There is no obedience to any created being if it involves
disobedience towards Allah, may He be exalted. But the father may prevent
him from going out for a voluntary Hajj, because he may prevent him from
going out on military campaign, which is a communal obligation, so in the
case of a voluntary matter it is more appropriate that he should be able to
prevent him from doing it.

End quote from
al-Mughni (3/284)

For more
information on the obligation to do Hajj immediately, please see the answer
to question no. 41702

Secondly:

Becoming
financially able to do Hajj is not obligatory, so the individual is not
obliged to work or save up money in order to do Hajj, because that without
which something does not become obligatory is not itself obligatory.

Shaykh al-Islam
Ibn Taymiyah (may Allah have mercy on him) said:

That without
which something does not become obligatory is not obligatory for a person to
do, according to the consensus of the Muslims, whether it is something that
he could do or not, such as becoming able to do Hajj, or earning the minimum
amount of wealth at which zakaah becomes due (nisaab). If a person is able
to do Hajj, then he must do Hajj, and if he owns the minimum amount of
wealth at which zakaah becomes due, then he must pay zakaah. It is only
obligatory if that condition is met, but he does not have to become able to
do Hajj or to acquire the minimum amount of wealth at which zakaah becomes
due.

End quote from
Dar’ Ta‘aarud al-‘Aql wa’n-Naql (1/212)

Shaykh Ibn
‘Uthaymeen (may Allah have mercy on him) said:

Is it obligatory
to accumulate wealth so that he may pay zakaah, and if one year has passed
since his wealth reached the minimum threshold (nisaab), is he obliged to
pay zakaah?

Answer: he does
not have to accumulate wealth in order to pay zakaah on it, but if one year
has passed since he acquired the minimum amount of wealth (nisaab), then he
must do what is required to pay zakaah.

The difference
between the two is that that which is required in order for something to
become obligatory is not obligatory in and of itself, whereas that without
which the obligatory act cannot be done is itself obligatory. Acquiring
wealth in order to pay zakaah means acquiring that which is required in
order for zakaah to become obligatory, and doing that is not obligatory.

A similar case
is that of Hajj. Do we say that the individual is obliged to accumulate
wealth in order to do Hajj? Or do we say that if he has wealth, then let him
do Hajj?

The answer is:
If he has wealth, then let him do Hajj; as for the former, that is not
obligatory.

End quote from
ash-Sharh al-Mumti‘ (6/96).

To sum up the
above:

So long as you
are not able to do Hajj, and you do not have the necessary funds to do that,
then Hajj is not obligatory in your case. It is also not obligatory for you
to work and accumulate sufficient funds to spend on Hajj. And it is more
appropriate to note that you do not have to give up your studies for the
purpose of working and accumulating wealth.

Based on that,
you should give precedence to your parents’ wish that you go to university,
and delay the idea of Hajj until Allah makes it easy for you to attain the
means of being able to do it.

For more
information on the guidelines on what is and is not obligatory with regard
to obeying parents, please see the answer to question no.
214117

And Allah knows
best.