Keeping it for one month before transplanting would severely limit its growth, with maybe a popsicle sized plant, and by the age of one month, would be starting to, or almost starting to flower, not an ideal situation as you would most probably end up with only enough bud for one or two joints.
The biodegradable paper/cardboard cups aren't all that good either, they take too long to break down and allow the roots freedom.
Buying a square plastic pot of around 5 litres and that fits in your PC Box, then planting your seed straight into the 5 litre pot would be best for the plant and best for the yield. Each time you transplant, the seedling takes a few days to recover, so transplanting 3 times would mean around one week of lost growth. Combine this with one week at baby seedling stage and one week recovery time from the multiple transplants would only give two weeks or so for vegetative growth before flowering started automatically, due to the plants age, resulting in rather small yields.
So really, starting directly in a 5 litre pot or so and not transplanting, will potentially give you the biggest returns.
Hope this helps,.........
Organoman.