Hi its nice to join your contest.
I use modern mid century style as you wish for this studio apartment. I didn't change the kitchen cabinet and bathroom as your wish for cut your budget. I just add more storage in bathroom and pulled wall bed. For more bed i use sofa bed if you don't want to use you can put it under your wall bed when you use your wall bed. and for dining table it can be fold up if you don't want to use it.
if you have any question and some detail please ask me