Here's why oryx cost more than deer:
An oryx form costs over twice what a deer form costs, and being a lot bigger, the shipping of that form is more. Plus, there are very few sizes in oryx forms, so more often than not, you have to do a lot of alterations to the form (unlike deer that come in every shape, size and pose you want). Tanning costs, whether you do your own or ship it out, is over twice as much. These bull oryx have skin over an in and half thick, and it takes a long time thin that skin down.
So, you pay for all the materials $120, and another $120 for tanning (those prices include shipping)if you tan your own, you're looking at $20 in materials, and 5 hours of your time, you're now making $110 for mounting an oryx. Average time is 12 hours for an animal like that (if you send your hide out), (caping, salting, form prep, mounting, and finishing). Now you're making less than $10 an hour, and that's if none of that money goes towards shop rent, electricity, etc., etc. So now you're asking taxidermists to make about $6 and hour. That's insane. I have no intention of working every night until midnight (like I do) for $6 an hour, and nobody can make a living off it.