This is the exact problem with the bloated costs we pay.
Street signs cost $10-$15 for non-customized direct from the manufacturer. Customized (street names) are around $25.
Street lights cost around $200-300 for a medium quality LED.
Traffic lights cost $250 as well.
Of course add the pole and installation....and all US$.
But the city is still using the same process they used 50 years ago for purchasing. Purchasing has evolved and cut out the middle men which create these huge prices (alibaba is a key reason).
In the past the manufacturer sold to a international distributor, then to an import/exporter, then to a wholesaler who then had local distributor. The city only dealt with the local distributor. Each person that touched the product doubled the cost. So a $250 manufacturers sales price turned into a $4000 sale to the end user. We can now get it for $250 + shipping (a 20 foot container costs $1000)
Now with something crazy called the internet you can deal directly with the manufacturer. The city should have sanity checks before they keep on buying from the same supplier who I assume has a cozy relationship with the purchasing department.