Doesn't have to be that spendy. Figure retail cost plus a $50 engineering fee. So, a basic XR50 shock from Works is $289, you're looking at $339 for one that will bolt in, get you the exact ride height you want, and be sprung and valved to match your exact setup, no fiddling, no fuss, no muss. If you aren't satisfied, they'll redo it till you are.
For reference, their app guide lists shocks down to 8.25" / 210mm long.