No. For reasons including -
The additional health risks. To you/your body, to the baby. Even with the donor egg the pregnancy itself has greater risk the older you get to the baby amd yourself. The birth can be more dangerous for you and the baby, intervention more likely. These issues can even lead to disability.
Potential disability. From a difficult birth. From bad luck. Genetic problems. Paternal age at conception has increased risks too, regardless of the age of the donor of the egg and the birth mother. Coping with disability is tough at any age, but will only get harder when you add in everything else relating to this.
Being 50 with a toddler. There will be grandparents who are younger than you picking up grandchildren from school. Kids pick up on this, and bullying is a fact of life, and would be ammunition. Health risks become greater the older you get so you would find having a child harder, and might not be able to meet their needs. Menopause with a baby/toddler. Chances of dying increasing and leaving the child motherless (parentless potentially, if your DH/P is the same age or older.) Almost certainly dying or needing care while the child is a fairly young adult. Even if you don't rely on them at all for care, they will likely feel responsible, and sad/unhappy when they're 25 with mid 70's parents that they can see becoming more and more frail while their cohort still has parents not much older than you are now.
The donor egg. Opens up a whole can of worms for them. You've no idea how they will respond to being donor conceived. Many donor conceived people are now adults who are speaking out about the way they have been affected by it. You don't know if your child would be at peace with it, or how they might want to proceed in future. It might be particularly hard for them growing up with a sibling who is your biological child. The potential for them to meet relatives in future and not know it. The potential for them to have access to that information and go looking, potentially causing problems in itself based on the reception they get. The potential that this person has health problems on their family or with themselves that they did not disclose to the clinic. There is only so much information even reputable clinics can realistically gather about donors.
The impact on your first child. The toll having a baby/toddler while going through menopause, following a pregnancy of such elevated risk could easily affect their life. Then having a younger sibling while you are older yourself and more exhausted. The potential for them to have to take on more responsibility for their sibling if age related health reasons occur. The potential for them to feel responsibility, even if you don't put it there. If you were to die or become ill while the younger child was still in adolescents, or even early adulthood, the older child could feel the need to step into a more parental and supportive role, even if you don't intend this.
The potential for the IVF to not work. The waste of those resources. The heartache and wasted energy. The toll of your body all for nothing. All, again, potentially taking away resources, financial and emotional, from your child.
Obviously as individual reasons these can be thought worth the risk. People canbecome ill at any age, not everyone becomes long term ill as they age, and you could be fit and healthy until 80. But you will be more exhausted. Even if you "age well" there are still normal ageing processes. With two parents who are around 50 at birth the chances of these things becoming a problem increases vastly. It's the combination of all these factors that make it a risk not worth taking.