The travel cot from Graco works as well. I think when baby is so light in their initial years, thing like support and all... probably does not make as much of a difference to when they grow up. BUT this will probably last you through the first year and max max, 18 months? Thereafter, you should consider getting a proper bed for baby.
My house is really small, so we are not getting a cot. Gonna borrow a Moses basket from someone for the first 3 months, and therefore, baby will sleep next to our bed just on a mattress. FIL was horrified to hear that his precious grandchild is gonna sleep on the 'floor' but I don't really care. Haha!