Well cost is always cited as the reason so many never get one. And there is no easy answer to the problem. When I first started bonsai I often would buy 2 or 3 "cheap sticks in pots" from nurseries every month for the 6 months a year the nurseries were open. I would drop around $50 a month on various plants that I'd drag home. Then I ended up with a yard full of sticks in pots that took most of my free time to keep up with watering and the few minutes a year of training each would need. I stopped spending more money on sticks in pots. I started to "save up" my "mad money". Now, once every year or two I have a little bundle, and can go out and buy one item for the year or two year period. I've spent as much as $650 on a single specimen. But that was after not buying anything for a couple years. That is one possible solution.
Joining a bonsai club can help you source good material. Definitely join the Montreal Society when you get there, even if you don't have any trees at the time, because you are living in an apartment. Get to know the members. For myself, I got to know one of our members who is currently 86 years old. He was / is in the process of downsizing his collection of trees. I was able to buy a Hinoki from him that was "local club show ready" and with time could be improved to be even better. It is a damn nice tree. The pot was worth about 3/4 of the asking price and I bought. it. It was less than "market", I paid only $250 for a tree that at a "Bonsai Business" might be several hundred more.
Point is, getting to know members with good trees, you will occasionally get offered opportunities to buy some established stock. If you have been "saving up" you will then have the "mad money" when the opportunity comes along.
Sometimes you can trade. I traded a male persimmon and a wisteria to another member for a really old boxwood. The member had a female persimmon that wasn't producing fruit, I solved his problem, with a tree I didn't value, as I had lost my female persimmon.
Another option is to trade labor for trees with and older member. Most bonsai societies have average age over 65 years old, if you are younger, and able to bend and lift, you can really help out the older members, and you can work out deals where you can pick up well developed trees.
Last is, if you take workshops with traveling artists, for example Ted Matson or Peter Tea, or any of the many that travel. Talk with them, tell them what types of trees you are looking for and your budget, and they often will work as middle men or referrals sources and connect you to someone selling something. Network.
Exhibition quality trees only come along once in a while, not necessarily every year. Plan and be ready for when you stumble across a good deal. Start shopping now, when you can not buy, so you are familiar with price ranges for material that you are interested in, so that when a good deal does come along you recognize it as a good deal. Because like the Mirai website demonstrates, some trees can be "over priced", and some are good deals even at the high prices, and sometimes a great tree will come along at a modest or low price. It is good to learn the market for trees you like, so you recognize the good deal when it comes along.