Depends on your budget, how you value your time, and the kind of rack you want.

When I first started I built a few Melamine rack they were nice but heavy and because they are made of wood they expend and contract all the time.

I slowly decided to move toward Expended PVC racks and after pricing the material I decided that it was not worth it for me to build it myself so instead I started buying Animal Plastic racks.

Those rack are light but sturdy, easily put together and come with recessed it which cannot really be done when building your own rack.