research process - What are some of the issues one should keep in mind while choosing between a fully funded offer and another with no funding?

I have been offered a place for a masters program in 2 places. One which is fully funded and another one where there is no aid that has been offered at the time of admission.

I guess if the everything else was the same between the two then the answer is obvious, which is to go for the funded one. But the problem in my case is this: In the fully funded case I have been offered a place in a research group I have no primary interest in (and no previous knowledge of) and something which I would not have definitely chosen if I was given a choice. So in sum, although it comes with a lot of money, the work is something I'm unsure if I will enjoy.

In the second case, there is no aid. The tuition fee + living is something which is not completely unaffordable for, I hope to manage those with loans and some family money. Aside that, I feel there is a lot of flexibility (or at least some flexibility), as I can choose my domain of work and my advisor once I have enrolled, and maybe been through a semester. Also the coursework here is a lot more closer to my preferred area of research.

Additional info: Comparing the two universities as such, the second one (the one without aid) is higher ranked than the other one (with full funding).

So given all this, how do you think I should make a decision and what is your opinion on the same?

Edit: Both programs are research-based and require a thesis.