Questions that can help you narrow down your search:
- What size are the typical subjects?
- How close do I want to be to the subject?
- What lighting conditions will the subject be in?
- Is the subject moving or not?
- What do I already have that can be used with an accessory for closer focus?
- How much automation do I need (auto-focus, body control of aperture, etc.)?
If you aren't really sure how to answer those questions, consider buying the Raynox to learn on. After using it, you should know what doesn't work about it or if it's perfect.
The inexpensive dedicated lenses I have used and liked:
Sigma 50mm f2.8 manual focus - KA mount, 1:1 magnification, good handling.
Panagor 90mm f2.8 manual focus - 1:1, basic K mount, excellent handling.
Pentax-M 50 or 100mm f4 manual focus - 1:2 and basic K mount, excellent handling
Phoenix 100mm f3.5 manual focus - 1:2 with diopter for 1:1, inexpensive but adequate handling - AF version is similar
The Tamron Adaptall-2 90mm f2.5 is a very nice lens and I finally broke down and bought one. The disadvantage here is getting the adapters and converter or tube for 1:1 and KA operation, which drives the price up.