I was in the same position 47 years ago that you are in right now. I started my first full time job and needed a better car. I came across a bare-bones 1965 Rambler Classic 550 (bottom of the line) with 7000 miles and the balance of the factory warranty that I bargained the price down to $1750. This was in April of 1965. I lived quite well without power steering, power brakes, air conditioning, automatic transmission, etc. I did finally splurge and for $37.50 had back-up lights and a windshield washer installed on the car. That Rambler saw me thrugh 4 years of employment, two years of more graduate education and two more years after graduate school. In fact, the money I would have spent upgrading to a newer, more luxurious automobile, went to the down payment on a house.
Stripped down cars don’t sell well, which works to your advantage if you have the energy to crank your windows open and closed, and keep the car to the point where there is limited trade-in value.
I don’t know what your driving needs are. If you are an over-the-road sales person, then the Yaris might not meet your needs. However, if your driving is mostly local and suburban commuting, then the Yaris may be a good deal for you. In any event, check on prices, have the car inspected by a good mechanic, and do your bargaining if the car checks out.
One way to improve the ride of the Yaris is to find an old time farmer that has an International F-12 tractor. Offer to plow a field for him. After an hour on the tractor, go back and drive the Yaris. You will think it has a great ride.
I like your reasoning on a buying a bare bones car. Back in the late 1950s, I found the Studebaker Scotsman appealling.