I owned an archery shop a short while ago. One way that we stayed on top if offering things the competitors didn't. We had a full selection of 'lefty' gear. In our case if any one person of the bunch was a lefty folks came to our store to shop because then they all could have a selection to choose from. In your case it's obviously different because it isn't retail. That being said, I don't think it would hurt to have 1-2 lefty's in stock.
Obviously I don't know what your inventory looks like or what your carrying costs are for the products. That all has to be factored in, of course. My suggestion, build 1 in the most popular two calibers. If they sell quickly build them again. If they do not sell in a reasonable amount of time move them off the shelf and have them via custom order only.
I'm not a big fan of $ sitting around collecting dust...