If you pick a very low cost area like rural prairies or maritimes, you can cut down on cost of land and hay. But you will be out of reach of shows clinics and coaches. And jobs. If you settle in Horse Central in the greater Toronto region you will be admirably placed for the dressage world, and jobs. but the prices will be urban high.
When you look at your salary, you need to calculate taxes and payroll deductions and retirement contributions if they are taken off your cheque. So take about 30% off the top which will leave you with about $50,000 a year or $4000 a month.
That sounds like a lot when you are an undergrad! But at least on the West Coast, figuring its $1800 to rent a one bedroom apartment and up to $1000 to board in a good barn accessible to the city, and gas is over $1.50 a litre, and $75 an hour for lessons, that $4000 will not go far. I am sure prices are similar in the GTA.
I am a college prof making more than your projected starting salary. I keep a horse modestly in self board and keep my monthly basic expenses low. I wouldn’t feel financially comfortable buying a $70,000 horse and keeping it in full training.
However, it really depends on what you mean by “compete FEI.” You are at 4th level now, and the FEI tests start at PSG. Here on the west coast those classes are offered at all the rated EC Bronze or Gold shows, though they tend to be under subscribed. Competing FEI might be as simple as firming up a few moves on current horse and moving up a level.
In that case, you already know the expenses and drill.
I would say anyone on a professional salary ought to be able to compete one horse locally and move up levels if they have a good enough horse and the right trainer on board.
But if by compete FEI, you mean have a string of quality horses and compete out of your region, maybe in the US, and win against established players in well subscribed competition: i think you might not have the money to play at that level. A lot of American amatuers are seriously wealthy, and there is much more money in the US. Plus $CAN is running 30% below $US so showing down there will be extra expensive.
A lot would depend on your own skill as a trainer. Can you start green horses and move them up the levels in a timely fashion with only a little trainer input? Or do you need to buy made horses, or be in a training program, to be successful?
And land costs vary a lot. Horse acreage in the BC Lower Mainland starts at about $5 million. A basic suburban 3 bedroom house is $1.5 million, a condo is about $500,000.
You could get a whole ranch in the back country for under $500,000.
Whether you can afford land will depend where you settle for your permanent job
I do think Southern Ontario has the most coherent horse competition scene in Canada. And therefore the biggest concentration of coaches. And all the Olympic competitors in every discipline. So in terms of learning and competing, that would be where to settle for sure.