Reduce your overheads
For many years now, cabinet-makers have realised the cost savings in outsourcing the labour-intensive work of manufacturing cabinet componentry.
Think of all the costs involved in running your own workshop: rent, lease payments for machinery (not to mention maintenace and breakdown costs), staff wages, power, waste collection. It all adds up, and you have to pay for it whether your business is busy or slow.
Instead of paying for all that, why not simply order the required components and have them delivered to you.