If it gets me better at building wheels, well worth it.
Simple enough and quite satisfying to build your own, plenty of info on the internet. I have done quite a few, just true them up/ dish them on the frame, use my thumb or a plastic handle pinched against the frame to find the high/ low spots. No need for a fancy jig if your are just doing the occasional wheel build.
New spokes and nipples also mount up the cost, if you can get secondhand complete wheels and change the hubs to what you want would be more cost effective.