I am not familiar with cobshop.
You can build a pretty good DIY 9 COB 450W light for ~$350
10 x
CLU048-1212C4-353H6K2 COBS ~ $80 use 9 of them.
9 x
Ideal 50-2204ct cob holder $18
MeanWell
HLG-480-C1400B driver. $150 plus shipping. Dimmable
9 x
ARCTIC Alpine 64 GT Rev. 2 CPU Cooler $80
Misc frame and wire etc. $25
12 volt AC/DC transformer to drive the cooling fans $3 you probably have one around the house already.
Check out the youtube videos by Growmau5 on how to build it yourself.