Probably $200 for a good pair of boots
Expect ~$400, and it's easy to spend $600 without much effort.
That said, look at my comment above in this thread; they do really last 10 years or more, so the investment is well worth it.
Hell, Schott will sell you a pair of made in the USA goodyear welted boots for 300$.
After punishing them heavily with hiking, working (concrete, dust, mud, stones, rocks, metal, paint...), running, sports, climbing... they are quite weathered but as good and comfortable as new. I just wish I could buy the same exact ones again.