Do you want open sights or peep?
The simple approach would be to hang around the stores, shows, and www looking at rifles made 30-50 years ago when most came with open sights and were factory drilled and tapped for both receiver sight and scope. Simple, but not easy, you would have to be patient to find a good clean example at a reasonable price.
Williams Gunsight charges $40 to drill and tap for a front ramp and $40 for a receiver rear. Their Foolproof peep sight is $75-$85, plus $22 for the ramp and $12 for a bead. About $200 by the time you pay shipping. Maybe some local outfit would do it cheaper. But not a lot cheaper.
Some CZ rifles come with open sights. I don't know what else, but catalogs are free.