since you have a good eye for your subject and want to try some close up photos why not consider a set of diopter lens to place on the front of your present lens,, they will not offer the same resolution as a macro lens (but close) and it keeps your cost reasonable while allowing you to further your photography skills,, a couple extension tubes will also work fine and should be considered as an alternative to the diopter lens,, the extension tubes can be purchased without any data (focus and aperture) transfer and will need to be used in a full manual mode so be sure your lens will support this,,
Derry