There are too many 'ifs' to give an answer.
NO! You cannot buy weanlings, yearlings or 2 year olds because you can buy 3 year olds and older (more ready to go to work and more marketable) for less than you can raise them.
NO! if you do not have the skill and knowledge to 'finish' a horse. Prospects, 'well started' and 'green broke' horses are a dime a dozen.
There is a HUGE market for any horse that is ready to go and do a job. I do not care if it is a team roping horse for a #1 or #2 roper, a Ranch Sorting horse, an Equitation horse, or a SOLID trail horse. It can even be a SOLID backyard horse that is safe and can be taken on a trail ride or go to a 4-H program or ????? If it is SOLID, SAFE, has no holes in its training and is pretty much 'Dummy proof', there is a market for it.
If it is 'almost' finished, or ---
OK BUT you have to longe or round pen it before you ride it ---
If it is OK BUT it does not load very well ---
Or he is OK BUT it does not get along well with other horses ---
Or he OK BUT hates dogs and isn't very good around little kids ---
A horse has to stand for shoeing, clipping, mounting, blanketing, bathing, saddleing, etc.
Are you getting my point? If there are any 'BUTS' forget making any money on a horse.
What we have found is that knowledgeable horse people are not buying horses -- The so-called Dummies are. (Not really 'dummies' but they are people that are a LONG way from being professionals and do not want to deal with problems.) These are Doctors, lawyers, bankers, business men -- people with 'day jobs', people that make good money and are people that want to keep their wife and kids safe.
What we call a 'Dummy-proof' horse is one that you can hand the lead-rope to someone and tell them to go have a good ride. It is a horse that does not come with a 'list'. If a horse has a list of instructions or 'don'ts' that come with it, you cannot give it away in today's market.