The best advice I was given, far after I had my first Minis was buy the best mares you can and breed to better stallions. A stallion is 50% of your breeding program. He can bring alot to the table, but can't correct everything. If you have wonky (not saying you do), but he can't be expected to correct overt flaws/faults. Then again if he has faults - bad legs, bite, thick neck, bad butt - you will have a herd of that.
Long story-short, I was given an 'opportunity' that was too good to be true years ago with a package deal. Being a novice it seemed wonderful and I bought 25 Minis in one big purchase. All the stallions were sold years ago and only a few of the mares were kept. A very expensive learning mistake on my part and it took years to correct. I'm always telling people don't make that mistake!
I've owned stallions since 2000, it can be a challenge at times, but I really enjoy the boys. Well not right at the moment when all are on full testosterone overload, but in general I like them, but I also won't hesitate to geld a stallion/colt. I expect my stallions to be easy to handle, non-aggressive and have certain qualities (conformation, movement, etc.) that work with the majority of my mare herd.
There are great deals out there, but you have to know conformation and pedigrees (if you want to breed I would highly recommend investing in both A & R online studbooks), you need to know what is desirable (conformation, pedigrees, looks, color, abilities) specifically for your area. Not that you won't sell nationwide or to Canada (or overseas), but most of your sales will be within a few hundred miles. With that in mind, what are they selling for in your area? Is there a market for what you want to produce?
As you breed dogs you know what that's like. You can have an uber-stud, but if there are a plethora of lower quality dogs available, you'll have a harder time justifying your prices if people are looking for pets versus show dogs. We're all facing that now. I see weekly Minis on Craigs List for $200 that is generally unregistered, often intact stallions or not very desirable 'broodmares'. It affects all of us that do try to breed decent Minis.
You can say your breeding for yourself, but what if you have all colts? Or years of all colt foal crops? Are you willing to geld them all? House them? It can happen. I have a friend that has had one filly in years of breeding (different stallions). It's hard to keep colts that are related to your mare herd, or daughters of your only stallion.
With Minis to raise a foal to weaning (4 months +/-), registration and keeping the dam/sire, you're easily over the $500 investment for that foal. So if you can't get that, and many areas can't right now. It's something to consider.
It might help you to network with people in your area and see if you cannot lease one for breeding. He comes to you that way, you don't have to send your mares out, but goes home too. Or see if there are like-minded breeders around that you can exchange breedings with, should you choose to own.