Assuming it was
this kit I assume the driver is worth $45 so I subtracted that cost, the XPG 4500K R5 at 5W, 50C, should be about 27% efficient and cost $1.75/PAR W.
To compare with modern COB, the CXA3070 5000K BB bin, $40 at AliEx, run at 1.4A = 48.4% efficiency and cost $1.58/PAR W.
When available, the Vero 29 V2 5000K run at 1.4A is 44.6% efficient and cost $1.24/PAR W.
If you wait until Vero29 V2.0 comes out, you could swap the XPG board out and run a Vero29 on that driver. At 3.6A the Vero would be 36% efficient and cost $0.55/PAR W. A alrge increase in light and a profitable move if you were able to sell the XPG board for more than $29.
We have com a long way in a short time