Before any other evaluation, check the spindle bearings to see if they are capable of handling real radial loads.
Manual or semi-auto drill/tap machines may not have angular contact (or tapered roller) bearings as they are only intended for axial loads. It would be rather a shame to discover you can't do any reasonable side-milling without a major redesign of the spindle.
I've no idea what the situation is in your country, but if used machine tools are that expensive I'd think a self-built thing from scratch would be better than that Burgmaster.
