whats the best way to do this? investment plan.

earning 40k (first yr uni) combined with g/f
want to buy a house next yr (230k)
w/ 46k deposit (hopefully 20%)

over 3 years, pump 50+k principle, as well as pay loan @ 9.0-9.5%

question
what happends if i wont to get another after 3.5 years? saying i worked out net equity of 200k.
use equity or sell? maybe sell and develop
also, buying another house would effectively mean i would have 3 loans! true,
what would be the ebst way to go about it.

saying that after 3 years we earn combined 100k.