That 150 STEEM would help a lot, an airplane trip from Portugal to Krakow is a little bit expensive, but I found a way to reduce the price in half, by spending more four hours. Which means that now it costs me 178€ (flying with Ryanair) or 223€ (flying with TAP). I haven't decided yet, but I think the cheapest the better, so not much choice available.

If I got those 150 STEEM, my flying costs would be covered and I would only have to worry at how am I going to survive there for a few days. Hopefully I will have enough...
Considering that I don't have much knowledge about the country, I'm pointing to stay on an hotel, but the prices are also not looking great, the cheapest that I found was 200€ for the 5 days.