sounds interesting. It is hard to imagine to have a 100W LED light at that price.
An appropriate quality LED-light of 50W, having a flicker-index of 0,01 I didn't found below 90 Euro. At 200fps you still can see some flickering. At 100fps it is OK.
Absolutely flicker free is the Aputure Amaran HR672S, 25°, about 4600 Lumen, but it costs about 250 Euro.
It would be interesting to know, at which fps-rate and shutter-speed you test these lights.
A simple test would be to use the handy in slow motion recording mode. Most (at least the iPhone) have a slow motion record at 120fps and 240fps to make a quick check.