Kanchanaburi/Myanmar Border: Possible to go short visit while border run?

Hi there,
Ive heard accounts that crossing the Kanchanaburi/Myanmar Border costs 900b, is that only for people who want to do in and outs? I have a Multiple Entry Tourist Visa and would like to visit Myanmar for a weekend and then return, what is the 900b cost exactly? If I drove all the way to Kanchanaburi myself – park the car and enter myanmar, how much will it cost go cross this border and stay the weekend?
Thank You in advance