A lot of this is going to be my opinion and others could have varying opinions too.

So, for me, I wouldn't even look twice at some of your horses, simply for being too low of a level. I cannot control what newer players do, but older ones, tend to use horses that are level 50 and higher for breeding purposes. Now, you COULD go lower than 50, but the minimum should be 50 between stud and mare as you add those two up to equal 100, divide by 10 and you get a foal with a training boost of 10, which equates to better foals that perform better.

Now I mentioned lower, because for example, I believe that I own some Saddlebreds and even plain Thoroughbreds that are different varying levels. So, I could have level 80 stud, I could find a level 20 mare, breed the two because the outcome will always be 100 and a training boost of 10 but then, I own some Thoroughbreds out of a really good stud, that their levels are 100+, at that stage, I could use any level mare because the stud would cover it.

When I had my Thoroughbreds up for stud, they were at least already level 50 and some even higher. So for me, I did at least range of 5 to 10k, sometimes even higher if it has genetics someone could want. If I have a stud up over level 100? Then he would be well over 10k, maybe even 20k if not higher because his PS would be high too, plus factoring in his BS too helps.

I know some people will put their horse up for breeding but it will be $500 and up and the horse is fresh off the assembly line, so to speak, meaning just got from Foundation Store, level 1 and maybe PS is at 32 or some low end number. Those often get ignored because even if it has genetics I want? I flat out ignore it because I worked hard on my lines and want to produce better foals and sometimes have foals with a training boost of 20.

I personally, would never put a horse up for stud or brood if they are below level 50 because I know that training boost really helps numerous players, especially when it comes to campaigns. Maybe a minimum base of 5k to begin with and then adjust depending on BS, PS, star amount and genetics. Then can raise higher at certain level increments, say at 500 per 5 levels, so if a horse is level 55, then raise price up to $5,500.

I always had my studs private because I have certain restrictions in mind for them, now, and I really do not want to flood the market with unwanted horses/foals myself.