Planning to buy microscope viewing live cells or fixed cells, mainly at 100X oil immersion or 40X phase contrast. which microscope works well upright or inverted microscope ???
it might depend on the task/objectives of your experimental work and analyses you want to perform (with regard to methodology: classical transmitted light only, fluorescence, epifluorescence, wide field fluorescence, etc., etc).
For a "crude" information and comparison of the PROs & CONs search e.g. by Google for topics/keyords: