Build or buy depends on your budget and how you value your time.

I have built several racks but have slowly moved away from that to buy racks instead.

I like for my rack to be sturdy yet light so Melamine is out of the question plus wood tend to expend and contract a lot.

I have replaced almost all my racks with animal plastics racks and could not be happier, I price building a rack myself with the same material and the saving would have only been about $50 not worth it IMO