Tank size won't be an issue for awhile. There are many other concerns with baby aros, such as tank mates, feeding etc. Is you tank top completely sealed?
I am worried about feedig too... Just paranoid that he wont eat anything I try. Top is completely sealed and his tankmates are just a crayfish and pleco, they won't be a problem, will they? Because I will take either or both of them out if I need to.
There are many considerations, the main being regional market, that have to do with the price.