re: Materials

Ron,
Thanks for the response, I was curious as to where you get your project lumber, wondering if you go to the mill or not. Like you, I also patronize a small family owned mill, only go to big box for construction 2 X 4's. I'm fortunate here in western Pennsylvania to have several such mills within a reasonable drive. My last trip was for cherry, I purchased about 70 bd- ft, cost me $205.00. Hard Maple at my favorite mill is $3.25 / bd-ft for select grade, and soft maple is $2.95 per, all 4 quarter and skip planned.
As for the finishes, yep, all have skyrocketed in price lately. 
Regarding your comment: "I wonder how long it’s going to be before this hobby is too expensive to continue.", the only way to address that is to charge for your builds. Unfortunately, all my work goes to kids and grandkids, so I'm limited to getting a free meal once in a while.
Your butterfly cabinet is beautiful, keep up the great work.