The exchange rate is 1:370 for a long time by now. So 199L$ are not 1 US$ as you say, but rather something like 0.60 US$. However you - and to some extent Rezzable as well - fall in the oh-so-frequent trap where you mix SL and RL economy. Of course 60 US Cents are not much, but 199 L$ are a lot. With 199 L$ I pay my office's rent for 2 weeks, or buy some nice pants or shirts. So from the buying power those 199 L$ are much closer to the 56 US$ you quote. Actually the buying power of 199 L$ within the SL economy pretty much equals the buying power of 199 US$ in the RL economy.