In fact, for elders, the price of birthday gifts is not important. What is important is the intention of children. As long as you can express your birthday wishes to her, it will be fine. Here are some suggestions and recommendations for you. I hope it can help you!
1. Practical small household appliances. Since you mentioned that your boyfriend's mother doesn't like extravagance and waste, a practical small appliance will definitely please her. The specific one you want to give depends on the needs of the family, such as soybean milk machines, hanging irons, cooking machines, etc.
2. Home decorations: If your boyfriend's mother likes to grow flowers, you can give her a beautiful bonsai, which can not only decorate the house, but also please her, and is also good for purifying the indoor environment. It is a good birthday gift.
3. Beautiful accessories: A beautiful hat or a silk scarf are good choices. Such gifts are not only not expensive, but also very practical. Your boyfriend's mother can use them.