I am an amateur chef that has passion in cooking.m looking for a small affordable oven to use for my baking but I am not sure which one to go for. i.e a toaster oven,a microwave oven or a mini oven. please advise.
I don't know what a "mini oven" is, so I will skip this one.
You should not, under any circumstances, get a microwave. A microwave is not suitable for baking. There are models which are supposed to be a microwave and convection oven at once, but I have frequently heard of them not turning off the microwaves when in convection mode, despite the manual saying otherwise. If you happen to get such a model, you will not be able to bake cakes in it.
I have a toaster oven of this type:
It serves me well for all kinds of cake and bread baking. Whatever has gone wrong with my cakes, I never had the feeling that it was the oven which was the obstacle to them getting better.
As far as I am aware, you cannot use the tiny toaster ovens which are only about 15 cm deep. I have never tried it, but I would be afraid that the heating elements are too close, and also you cannot fit a cake pan in there.
A good combi microwave can do it, but the top might cook a bit quickly.
The one we have is a Panasonic, and has microwave, grill and convection functions, as well as combinations of microwave with the other two. The convection mode uses a top element and a fan hence the top of the food may brown too fast. Foil should help. The controls, cooking in metal, and power consumption data (both in the book and tested by running it off a 6A circuit breaker) rule out the microwaves coming on when they're not supposed to, unlike some models which rely on turning down the microwave component to zero with an imprecise dial.
This wasn't cheap but cheaper models are available. Look for the manual online to find out more once you've identified a model.