50nl is incredibly fishy so yes it is absolutely realisitic if you have some idea of what you are doing. Don't have any nl50 hands in my database anymore but i think the rake was quite a lot. For 6max i seem to remember it was something like 5BB (just to clarify bb = big blind, BB = big bet = 2 bb) so 10bb/100. But somebody that plays nl50 could give you a much more accurate idea. But it is an easy level to beat with hardly any remotely competent or active regs and tons of terrible casual players.