Hi Billy, i hadn’t costed this build but since you asked so nicely
I already had the junction boxes, cheap 100K stepped attenuator, eye bolts and cable clips so probably around £20.00 in what i used from my own stock.
The rest i bought in and that lot came to £273.00. Mainly because @anon58740919 gave me a good deal on those SolStrips and I won that driver in an ebay auction for £28.00.
The total build cost was fully covered by the sale of my cob rig