I have a totseat, its wonderful!
DD is now 14 months and has been fine in it, just come back from hols and used it lots there.
I have a` friend who tried one with her DS when he was about 8 months ( i think) and i think it wasnt that great - a bit young. DC really needs to be sittign up well on their own.
Try ebay? Though when i was looking they werent going from much less than the retail price