Looking at the odds by bookmakers, seems that this match will be balanced as the odds show that none of both become favorite.
Spain with about 2.7x and Germany with about 2.8x, so it is hard to bet on which team to win the match if we are relying on the odds.
By statistic during this tournament is also a bit similar because both teams are unbeatable so far but Germany with 1 draw while Spain with perfect wins.
Both team to score seems to be the most attractive market to bet because it is about 1.75 so I think it is better choice than to bet on 1x2 market.
In my opinion, BTTS is too risky since one of the teams (this is enough to lose the bet) may turn out to be good/lucky in defense. 1.75 does not compensate for the risk that one of the two teams will not score a goal. By the way, the first half has already ended and the score is still 0-0, I think towards the end of the game the teams will be less and less inclined to take risks, so the probability of a draw is growing very quickly, now this outcome is rated as the most likely.