We will be staying two days and nights in Murren in late May, and hope to do some easy hiking. Do you think hikes will be passable then? How much does it cost to get from Lauterbrunnen to Murren? I've had trouble finding that information. I don't think a BO pass will be practical since we are only staying two days.
Easy hikes should certainly be possible, but of course that's something that's difficult to predict. The temperatures in Mürren appear to be well above freezing this week, so I'm assuming the snow will be gone by late May.
The trip from Lauterbrunnen to Mürren via the BLM route will be CHF 11.00 PP each way, unless you have a Half-Fare card or one of the other passes. You can see the details on the sbb.ch website.
One point to note is that two nights will provide just one day of hiking, once travel time is factored in.