What's wrong with birch ply?

You can make your own I think Lance a plan for sale.

To put the Birch price in perspective

http://www.luthiertool.com/neck_angle_jig.html

We use Mr. Woolson's jig made from the OLF plans to handle coarse trimming of the neck dovetail or tenon, and a separate shop-made jig for cutting the body socket or mortise. We are making up a couple more Woolson/OLF jigs (two for local builders and one for a student), and materials cost with higher grade materials (phenolic covered die board, Bessey/Armor auto-adjusted toggle clamps, corrected version of StewMac M&T templates in Lexan CNC machined by yet another local builder) appears to be under $140 per unit, assuming I did the bill of materials order correctly.

One thing to note for jigs which reference body geometry to set neck joint milling angle (including Mr. Fox's, Mr. Woolson's, and the derivative offerings from LMII and Luthier Tools) is that they are only accurate when the heel is untapered or the neck mounting area is dead flat for the entire width of the neck at the body fret. With a nicely curved neck area on the body and a tapered heel, a correction based on the degree of heel taper and the curvature of the body in the neck area must be added to the angle set by the jig.

I made this one a few years back from watching the video on you tube. All parts were scrap except the "angle aluminum" and it cost about $10. I used 3/16" plastic panel (also scrap) for the mortise and tenon templates. I though I would upgrade a while back and buy dovetail templates from LMI but when I got them they were so close to what I was using I decided to keep what I was using. If you want those (unused), I'll sell them for $20 + shipping. (LMI PART SKU/SPMTD)