Hey Mike
I guess we all have different experiences and budgets,I’ve made a jig very similar to the jig like the one I gave a link for above ,I gave the jig to my local High school woodshop 4 years ago and it’s still in good working order. There’s nothing wrong with factory-made jigs and they have the advantage of furnishing instructions plus if they’re made from metal they may be more durable,but if they are damaged you need to replace them or order the damaged part. With a shop made jig you can just make a replacement part.
woodworking classes, custom furniture maker