You could make your own cuirass by purchasing the components from somebody willing to supply them to you and then assemble it – this is bound to be at least a bit cheaper than buying a fully assembled one, as you are not paying for the time to put it together. However, if you have got this far, you may well be ready to try something a little more radical.
Find some plans, buy your raw materials, get out your tools, and start building. It is that simple.
On the other hand, if you do not quite feel up to a full-scale reconstruction of this kind, or perhaps you don’t have the room or the time to spend polishing it (they need a lot of cleaning), there are alternatives, as you will see.