Well you certainly do not have to buy that set in order to get Klingon text! There are free fonts, images, all kinds of stuff available online.
Also if one downloads some of the free models, you’ll get free textures HOWEVER it’s all considered “non-commercial” use only normally. I mention this because if you want to look at any to get ideas for your own, that’s what’s free and safe to do.
Also, somewhere online there was a website that had an online utility to make your own alien script with. That was kool, but don’t recall atm where it is.