Whilst its perfectly possible to build your own trailer legally etc, once you've bought all the bits and put it together, the costs are very close (possibly more than) it would cost for a new one anyway. There's many trailer manufacturers and since these are relatively simple construction and bolted together, lots of options for bits you need etc.
Also if you use a trailer regularly, you'll realise that there's more to trailer design than a simple chassis, load bed and wheels etc. There's little touches like clips, fastening hooks, etc in the right places, well thought out storage for ramps etc which a new trailer will undoubtedly have.
Also if you use a trailer regularly, you'll realise that there's more to trailer design than a simple chassis, load bed and wheels etc. There's little touches like clips, fastening hooks, etc in the right places, well thought out storage for ramps etc which a new trailer will undoubtedly have.