I've dabbled in all kinds of macro through the years. I've done the tubes, reverse ring adapters, add-on bits and pieces and true macro lenses. There is no sub for the latter. The cheap tubes work great, but they are harder work, and once you have them on, the biggest problem is you cannot go straight to normal view.
Have you looked at Nikon's cheapest macro? the 40mm 2.8? because I hear it's great for the price. Sure you have to get right in close, so it's not ideal for active bugs ... but for still life macro it's excellent.
I've been through them all - cheap zoom that claimed "macro" at one end or the other, add-on 'magnifiers', macro tubes, reverse rings, and then true macro lenses. I've had the old 60mm 2.8D which was a cracker, if you can find it used - go for it! I've had the 105mm which is great, but expensive for what it is, and now I have the sigma 150mm 2.8 macro with OS - which seems perfect. Pricey, but, I'm done with the tubes thing.
As mentioned, there are some gem macro lenses out there, you just have to do the research.