This hotel is in a great location for walking to a handful of booking joints, and also convenient to the block of whitey central pubs/lucy's. I think it can be booked for less than 400K per night via Kaha travel desk at the ferry terminal.

http://www.goodwayhotel.com/

This place also has a VIP lounge (as well as a van service, but that probably ain't free) at the Batam airport, though I've never been inside and the website doesn't say anything about it. You can get free wi-fi access (I assume it's from the Goodway lounge) at the A1 and A2 gates at the Batam airport as well as the little restaurant next to the Goodway lounge.

rooms are old, but the location is good for ktvs by the sedona area. 320 with kaha i believe.