I applied for a job about 10 days ago and today I got a mail response asking about my salary expectations. They did not say they are interested nor anything else about my application, nor did they invite me. I'm German and want to work in Spain, and the company I applied to is German but has a small office in Spain (and one in another country). I think they are about 80 people in total with only small teams working abroad. I already had some preliminary talk with the HR person before applying and (s)he told me that the salary would be lower than here in Germany but considered high in Spain, without giving exact figures (of course). I already have an offer from another Spanish company where I worked before, but for practical reasons I'm considering not to go back there.
I'm not completely sure why they would ask this - my guess is as they are a small company and have only a few people working abroad, they might not really know themselves what they should pay me. I know that there's a ton of similar questions, but not with my situation (small company, applying for a foreign office) so maybe someone can help me figure out the smart play.
I'm planning to think of a figure based on the Spanish average and the other offer. After a quick look I think that the other offer might be underpaid, so I may say a number that is more "average".
Is it wise to say that my "offer" is based on those two things or is it better to just state my number without any explanation?
I already made peace with the lower salary in Spain, but still I want a "fair" salary and fear that with my answer I might a) undersell myself or b) put me in an uncomfortable position. E.g. if it's too high and they might decline or offer me something lower - in case I accept it nonetheless, they could see this as a kind of deception?
If it is relevant, I have less than one year of experience. Applying for a Software Engineer position.