Dortmund have done quite well in the Champions League this season, they managed to beat many strong opponents, but in the final match they had to admit that Real Madrid was a very difficult team for them to beat. Even from the first half, Real Madrid played a fairly aggressive game by putting pressure on Dortmund with the many attacks they carried out. But it's true as you said, Dortmund didn't build a team with money, unlike other teams where they bought players with quite expensive prices but in the end they failed.
So, Dortmund success in becoming runners up in the Champions League this season is quite impressive and of course several of their players will experience a significant increase in their release clauses in the transfer market this season. For Dortmund, of course, this is a pretty good aspect as they will continue to sell their stars to get a lot of money and maybe that tradition will continue in the transfer market this season.
Actually, Dortmund have impressive performance in the final match against Real Madrid and success making many great attempt but Thibaut Courtois made many crucial saves and success without conceded any one goal yet. I think must appreciated with Dortmund achievement in Champion League for this season after qualifying until final round and eliminated many top opponent teams from Milan on phase round, Atletico Madrid at quarter final and kicked out PSG in the semifinal round.
Faced Madrid in the final, Dortmund have aggressive performance on the first half match but Thibaut Courtois success played on the top level perform make difficult for Dortmund scoring goals. I think for next season Dortmund management should defend their squad and give permanent contract for Jadon Sancho with impressive performance on second half season.
Yes, actually Dortmund were able to perform well and in the first half they were able to keep Madrid's game locked in, but Real Madrid has another advantage, namely the mentality of their players is not easily shaken. In the second half Kroos and his friends tried to combine the rhythm of the game so that they were able to escape the pressure and managed to score a goal. I quite enjoyed the game between the two teams because previously I thought Los Blancos would be able to dominate throughout the match.
I've always respected Borussia Dortmund in the world of football, especially with the way they use little resources to get what they want. This happens despite many clubs spending 100s of millions and may still not be able to achieve what the club would. But suppose I said I was not surprised that Dortmund played the final of UCL this season, in that case, I am lying because it started from the way they played their home league to the many questions of lack of form and were to face clubs like PSG that regularly prove to be a good contender and would drag themselves to the lockout stage but was defeated again by Dortmund in the semi-final, and Milan that played the last UCL final and Atletico Madrid that was also a very good and determined team. Kudos to Edin Terzić and more reason why I believe they deserve to win the UCL this season but I still see a lesser self-belief in them than Real Madrid's team regardless, and that could be one of what cost them this season.
However, the team tried so well, there was no goal in the first half and if not that the defence of Real Madrid was more powerful than what they prepared for, they would have at least scored as well. Thanks to Thibaut Courtois on the side of Real Madrid who is now rumoured to be the world's best goalkeeper, and no doubt, he did an excellent job this season in local and external tourneys. But it could have been different if it were to be a different club, he might have found it more difficult faced with seasoned strikers, as there were also a few lapses on the side of Dortmund, but overall, these guys did excellently well as they were determined to win, only that they met a better team and thanks to Dani Carvajal and Vinicius.
Nevertheless, this is an added experience since it's in the 96/97 they last won the UCL, getting closer this way often will only spell doom to their opponent one day and deliver the trophy into their hands.