The 5k/10k, 10k/20k and 20k/40k tables have a cap of 150 big blinds whereas the rest are 200bb. Was this done for a reason? It would make more sense if all tables had the same limit of 200.
I thought this was strange too! I never played poker on a cash site to make a comparison. There are a few other tables that are not 200BB at lower stakes too - HU particularly. It seems strange, silly and random to change the buy in amount.
I guess its just another strange random RP phenomenon!