What prices are you looking at my friend ?! I see the 1700x regularly on sale for 270-280$ and I'm talking of course about US pricing since that's the baseline since every country has different taxes and amount of stock.
You have choice with the b350 and x370 and the b350 is always cheaper and just as good, again US prices.
Like people said, it can last 3+ years and I'm comparing this too Intel. 1-2 year vs 3+, I see clear winner regardless if you intend to upgrade or not .
People don't just need good coolers to overclock, some live in very humid and hot ares and again I'm comparing it to Intel, AMD has better coolers, end of point.