I came across this page:
Product Review: A Comparison of Two Quantum Meters - Li-Cor v. Apogee — Advanced Aquarist | Aquarist Magazine and Blog
I thought that it might be interesting to some of you. It compares relatively inexpensive Apogee meter with more expensive Li-Cor model.
If you want to save a little bit more, you can get the Apogee sensor, and use digital multimeter:
PAR meter vs PAR sensor from Apogee - Aquarium Plants
Here is the comparison of inexpensive Apogee vs more pricey ones.
Apogee SQ‐120 vs. Kipp & Zonen PQS 1 vs. LI‐COR LI‐190 vs. Skye SKP 215