"...price around 1200 to 2400 Baht for 3 people (individual beds)..."
For your budget you could get 3 separate rooms around 600-800 baht each. Having a hard time coming up right now a cheap hotel with 3 beds in one room. Maybe a twin with a dinky pull out-roll out bed???
Are two of you a close "couple" that can share one bed?
Three rooms in these places should be under 2400 baht.
Ice Inn. (Good location for walking to many things. Apex nearby.)
Charlie Place. (Better than above places.)
Katesiree House. (Around corner from Charlie Place on Soi Boukhaw.)
November means some hotels start raising their prices for high season. More tourists show up when it gets cold in Europe and Canada. Quite a few small guest houses on Soi Boukhaw.
Lots of time between now and November.