I don't know how broke you are but there are many sites that sell plastic pots and the variety is amazing. They look just like the real thing but sell for a small fraction of the cost of the real pots.
[url=https://www.dallasbonsai.com/store/plastic_pots.html]Here[/url] is a nice selection of pots and at a very inexpensive price when compared to
the baked variety.
Also, I have been using many different containers for 'growing out' trees that I'm training. It's just too expensive to put them all right into Bonsai pots. I use anything that is low and fairly wide for training plants. They are made of wood, plastic etc. Just about anything that will hold potting media but will allow free drainage.
I'm going to order some plastic pots from the site I linked you to above for the trees I've got that will be the best candidates for display trees next Summer.
Hope this helps some.