IMO, Emissions are the cost of doing business. Can you do it cheaper - yes*, buy pre-emission equipment. We as a planet, country, province/state have agreed that certain emissions standards should be met. Actively seeking out and overusing outdated equipment is just a legal (but immoral?) loophole to that. Deleting emissions equipment because we don't like it is cheating the rest of us. Whether you get caught or not is not the question. We all have to sleep at night, and whether you do that with a $5000 luxury mattress paid for with pollution, or a second hand one and a clean conscience is for each of us to figure out ourselves.
*Can you actually do it cheaper? Generally we don't directly pay for environmental emissions, but if we did - I don't know. What the cost of a ton of CO, or NOx, or any other pollutants are worth plus the costs of trucking them to a repair shop. What is the cost of little Timmy getting sick, or not being able to play. I don't think you can do it cheaper, you are just "stealing" from the rest of us.
The vermiculite mine in Libby, Montana killed hundreds of people so their owners could make more money and this debate in a lot of ways is no different.
Also, just because someone else does something doesn't mean it's right for us to. ie a 3rd world country, still burning coal for power, and not caring about emissions on their tractors is different than what a lot of us face.
Having said all that I have an old pre-emissions tractor, for the same reason I drive an old chevy pickup. It's 70 HP, 4x4 and 3 years in, including purchasing it's cost me less than $5000 Canadian. It's what I can afford, and I do sleep well at night.
One other thought - in a lot of cases the equipment can run with a failed emissions system. They are de-rated, or otherwise "broke down" because if it wasn't programmed that way so many of us would continue running them (that doesn't apply to plugged cats/ particulate filters). They are there to "force" you to do the right thing.
Each of us contribute our tiny part to either the solution, or the problem.