If others with more money think the same, the matter is settled for you. Set the boundary for yourselves: either you are lucky or not. That is called fate.
You are only "briefly" done with the broker. Is the exposé "waterproof"? If you know how much still needs to be renovated (10k€, 50k€, 100k€) and how much comparable properties cost, you can clearly set the limit. 250k€ + "offer euros" + purchase costs will definitely end up at 300k€. + renovation. What is the heating with? Rating F, G, H...?
The owners were also present during the viewing. The heating is gas.