Question
Context
I've applied for multiples jobs at different companies. Just yesterday, I interviewed with company A and today I got a phone call from the same company saying that they're interested and want to send me an offer.
So far so good, but I was bit astonished when just a few moments ago, out of the blue, I got a call from company B saying that they want to interview me.
Key points
This is my first job. I have a Master's Degree since the end of January 2021. Although I have been made offers by companies outside of my field, I haven't accepted them since I'd really like to work in the field I graduated from.
Company A has offered me a good contract for a position outside of my home country. The job is in a country which is one of the best in the field, and is likely to have plenty of connections with expert organisations.
Company B has only offered to interview me. The job would be at my home country, but would likely pay worse than what was offered by company A.
Although both jobs are in the same field, the job at company B would be a much closer fit to what I'm looking for. I am somewhat afraid that the job at company A won't be challenging enough.
Both companies are multi-national, and my overall goal would be to work outside my home country.
Company A really needs someone to fill the position and they're almost counting me in. They gave me only until tomorrow morning (at best, and it would be already with some "favours") to give them an answer.
Options I'm considering
The option I'm most inclined to take is accept the offer of company A and politely decline the interview chance with company B. This would be good due to point 2, and would already fill the goal of point 5. The main problem I have with this is point 4 above.
(This point is only here for the sake of argumentation, but it is nothing short of madness in my opinion) I can decline the offer with company A, and try my luck with company B. This would be good because the job is closer to what I'm looking for (point 4), but I'm basically walking through fire since I have no guarantees I'd be hired, nor that the salary/conditions would be comparable (my home country tends to pay a lot less than other countries).
The only other option I can think of is in a grey area in terms of my view on work ethics (and thus, also the major reason of me writing this question). I can sign the contract with company A and do the interview with company B. The work with company A would only start in October, so in the meantime I could probably do the interview with company B to get a better read on the situation. If they offer is comparable, I may be inclined to chose company B due to point 4.
That being said, this would probably leave me on bad terms with company A, since I would have already agreed to be working for them. Even if I wait some time after the job starts and leave during probation, I don't know if it would be seen in a good light.
Final thoughts and actual question
If company A would have given me some more time (I've asked and they really cannot/are not willing to), I could probably work things out. But, in any case, here is the main question: I'm probably going with option 1. Is it worth to string company B and do the interview with them, so that I can later chose option 3? If so, is option 3 actually unethical? I know it doesn't sit that right with me, but then again I'd probably be overworked by a company if they told me "we're really in trouble and need you to work overtime so that we can end this project"...
Answer to Philip Kendall (too long for a comment, and might be useful to the post as well)
Yes, I definitely agree with that. That being said, I'd like to add a few points:
The company is not the "direct" contractor. Yes, I'd be working under them, but the job itself is a service company A provides to another organisation. That organisation does have its urgency (the job must start in October).
The reason company A gave me was as follows: "This offer would have to be processed internally, and then be sent through an international staff and the country where the job will be done. This can take around 2 weeks, which would leave us with no margin to search for another candidate if we give you more time to think and then you decline on us".
The offer being undervaluing me is actually my biggest concern (the fact that it only asks for a Bachelor's Degree doesn't help either). That being said, I am somewhat desperate to a job on the field since I've been looking for so long and little to no interviews. Also, I might make it easier to find a more suited job down the line, since the place is really close to one of the most prestige centres in the field (and has close ties to it).
Update
I've decided to go with option 1. At the very least, I want to give this job the benefit of the doubt. I've let company B know that I took the offer of company A. Still, I told them that I'd still be open for an interview (if they're interested), since I haven't ruled out working for them in the future. But for the next couple of months (at least), I wouldn't be able to accept an offer from them.