Instead of buying a shelf pin drilling jig, consider using a piece of peg board and either a 1/4" VIX bit in a drill or a plunge router with a 1/4" up spiral bit and a bushing, if you won't be making a lot of these cabinets. The accurate hole spacing of peg board makes it ideal for making a shelf pin drilling template and it's much cheaper than any of the shelf pin drilling jigs on the market. I would only consider buying a jig if I was going into the commercial production of cabinets. A shelf pin jig made from peg board will easily last through a whole kitchen remodeling cabinet building project.
Cut the peg board to width and length to fit inside the cabinet so that it can be clamped in place against the inside side of the cabinet. Hint - Trim the size of the peg board so that there are two rows of holes (one row for the rear pin locations and one row for the front pin locations) with the bottom and back edges of the peg board against the bottom and back of the cabinet (This will help to easily position the holes on the opposite side of the cabinet). Determine the row(s) of holes that you will use for the shelf support pins and mark them. You will need to enlarge these marked holes. Remove the peg board and drill the marked holes to snugly fit either the 1/4" VIX bit or your router bushing.
This piece of peg board has now become your template for drilling or routing the shelf pin holes. Place the peg board back into the cabinet, position it so that the enlarged holes are centered where you want the holes for the shelf pins and clamp the peg board in place. Now drill or rout the holes. The VIX bit in a drill will do a good job, but the plunge router method will leave cleaner holes.
Remove the peg board and place it on the opposite side inside of the cabinet. Don't rotate it - you want a mirror image, so the back (rough) side of the peg board will be facing out this time. Double check your positioning and clamp the peg board in place. Now drill or rout the shelf pin holes to match the other side of the cabinet.
My peg board shelf pin jigs were made about 15 years ago. I don't make many cabinets that need shelf pins, so they have survived very well and hang from a hook on the wall of my wood shop, waiting for my next cabinet project. I could easily make new ones, but will keep these as long as I have the space for them.
Charley