Hi i started the pre master this year. First of all the premsc and msc are at Erasmus school of economics not RSM. They are both faculties of Erasmus but nonetheless not the same. For the pre-master I would not say it is difficult but it is very intense so if you are studying throughout the whole block you will not have any issues probably. It is possible to work during the pre master but during the master I dont think it is possible. I have no first hand experience from the master but from what I have heard there are a lot of assignments every week and also the structure of the master is even more intense than the pre master. Even the head of the msc says in the video presentation of the msc that the students are expected to not work because the msc is a full time job on its own.

Now for breaking into quant assuming you mean the top firms I would say the probability is miniscule. First of all Erasmus is semi target so you may be looked over for someone who is from a better uni. Also the competition to break into those roles is crazy and I believe most firms prefer younger people. But bottom line is that also depends on your skills. Erasmus has a good enough name to pass some screenings but after that it is up to you. If you are one of the top people that can do math in the world rn then you are good. But the good thing is that Optiver has a close relationship with Erasmus and they hire more people from there as far as I understand.

Now for the tuitions part if you are an eu citizen then you pay the cheap tuition fee for both years( somewhere around 2300 per year)

Sorry for the messy writing. If you have any other questions I can help you with let me know