I will rush-buy a stone works on occasion in order to bring my happiness back above zero, but in general I consider it a poor investment. When looking at rush-buying I look at the gold/hammer cost. SW costs 320 gold, vs. 75 hammers. That's over a 4:1 ratio. Compare with the more expensive buildings like the Stadium, which is 1350 gold vs. 500 hammers. That's less than a 3:1 ratio. A nuclear missile is 2:1.
You can argue that the extra hammers you get from rush-buying SW partially offsets the cost, but that's going to be true whatever building you buy. (i.e. pay 1550 gold for a Stock Exchange, but if in so doing it earns you an extra 25 gold during the 10 turns you would have spent building it, then you're really paying 1300 gold)