Dharma is the ultimate solution to one's problems and sufferings. While not everyone's due to their own karma is ready for the medicine (dharma), the very least we can do for them is to give monetary support and whichever means depending on the situation the person is in. If we are unable to help with pujas and monetary aid due to lack of funds, we can always do virtuous deeds and dedicate the merits to them.
Certains problems do require pujas and prayers to alleviate the problem such as spirit disturbance and black magic. Again, dharma and the underlying compassion and teachings of karma is the ultimate solution to these problems. However, it takes time and understanding to comprehend the teachings of the Buddha. So quick solutions which can bring immediate results would be more appropriate.
Conclusion, it all really depends on the level of the person's mind. When some people's karma has ripen, it would be difficult to help in any spiritual form and only possible with material form.