If you want to do macro cheaply, get an extension tubes and slap it onto a 50mm.😎 Don't worry about image quality issues. All that empty air causes 0 image degradation. It'll a challenge to focus at first (no auto-focus or unreliable auto-focus at best), but once get a bit of practice in, it gets easier.
There are macro filters you can attached to the front of your lense, but I have no experience with those. I don't know how well they work. But they're also fairly inexpensive.
Finally, there are macro lenses (the work the best), but can be expensive. Scratch that, they ARE expensive. Usually twice the costs of a similar non-macro variant.