Olympus 25mm f/1.8 or Sigma 30mm f/2.8?

I suppose timing is everything when you buy a lens, but I presently have both lens that I purchased brand new. I wouldn't normally buy both lens since they are so close, but since I could buy each of them new for $132. (Sigma 30mm) and $299. (Olympus 25mm) and $331. total --- out the door for them, it made little sense to pass up the opportunity. I have experimented with both lenses in low light situations and while they are quite different speeds and FOV, there is no question in my mind I could easily get by with just the 30mm F2.8. If you needed a slightly wider FOV, then go find a Sigma 19mm F2.8 for very little (which, I also bought brand new for $135.), and that too would do quite nicely for very little money. Are there times you might need a faster lens? Certainly, but then you have some funds left over to use the Big Boy (like my Voigtlander's 17.5mm F0.95 and 25mm F0.95), which both practically live on my E-M1. And yes, in spite of the redundancy of my lenses, there are times you want a very small and light weight decent alternative lens. I simply really enjoy these more natural field of view options, as opposed to just about any other focal range of lens. It is never bad to have options, and in the micro 4/3's world we simply have more options than just about any other type of camera owner.

My suggestion, buy the Sigma 30mm F2.8 now, but shop a little and find the right and best price so you have the means to have some funds left over to buy the other primes (if you want or need) down the road.

Dale