A cycle-rickshaw from the bus stand to the Shait Gumbad Mosque should run around Tk 10.
Unless you're in a hurry, you may want to just walk to the sights from the bus stand. Head west along the main road, a fairly nice walk save for the speedy honking buses. The first sight you'll come to is the dargah; start asking around for it after about 5km or so. Shait Gumbad is another 2km or so west along the main road from the dargah turnoff.
