I use - ₂ ᴍᴜ 4* [TB11] Zz nd1nd2 LpLp Patn2patn2 [$] - for my horse name titles.  The first number is generation, then Mu for mustang, star level, training boost level, all the important genes.  Plenty of people use just names, or if they are selling foals keep the "Parent 1 X Parent 2 Foal" name.  I've bought horses like this, though it means I need to investigate into the horse a bit more.  I like labeling things, even though it can take a bit of extra time when the foals are born.  Sometimes I wait until they age up before I give them the full name, and just mark their generation and star level.  I used to put in their 3E3G, but I found I really don't care about the individual level of their confirmation stats, just their star level.  Even 1* horses can produce a 5* foal with the correct pairing.

Foal training not being done is a complete deal breaker. Foal training is what gives them the full training boost, which directly effects the amount of stats they can gain throughout their lifetime. Adding onto this, most people will not buy a horse below TB10.   Premium makes it easier because you have your own training facility and can click through them, but even without it, it's important to put them through it.  I can get most done in 2-3 days of birth by just checking in during daylight hours and running them through real quick.

Pricing and what people will buy is very individual.  I know a lot of people struggle with gaining bits on here and have strict horse limits so they aren't often looking for horses.   I generally have bits and space to buy whatever I'm feeling, so here's my criteria.  I'm only interested in foundation, low generation, or wilds.  I don't care too much about * level because I can breed it to where I want it (though a 1* foundation horse is significantly harder to get to level 50 than a 4* wild would be).   I'm generally on the lookout for horses in my breed with variations to their markings, horses that have a lot of markings (wilds and low gens), and sometimes I'll pick up rather plain wilds because they aren't too difficult to raise to 50.  

I price my horses high, but I really only sell horses that come out with variations, multiple genes, rare genes like manchado.  All other foals I retire.  Sometimes I'll keep a foal until I breed the next foal out of the pair (looking for variations or the combo I want) and then retire the first foal bred.  The market is flooded with randomly bred, single gene, low TB horses all over and no amount of 'this would make a good show horse' is going to make them sell.  It's harsh, but I'd rather wait around to get that one horse that sells for ~15-30k than put up a bunch for 1-5k that sit around not selling.  If a horse isn't selling after a random amount of time (aka, whenever I remember that the horse has been on sale for a few weeks) I'll just retire it.  I've done this with 4 and 5* horses, because sometimes the market just isn't there for a plain bay, even at 5*s.

I totally get what you're saying Nittrous but I've sold 35-40 $1k-$7k horses per month.  There is definitely a market for them especially when they're nice horses for a price that's dependent on their individual attributes. I typically have 40-50 horses per sale at a time and only 5-10 don't sell. (I'm trying to get away from having this many on the market but I'm trying to create a full herd of 6E BS horses and figured I'd sell the ones that are still good but don't make the cut for my visions.) I've also had horses that didn't have the full foal training have a higher training boost than their parents but have definitely noticed that horses fully foal trained sell much faster. I really appreciate all of the info!. I will definitely make sure I finish foal training on all horses. I've been playing for yearssss but a lot of things have changed somewhat recently. I also will retire horses that don't sell but I'm a ridiculous empath and become attached and it's sad having to retire horses. 🤣

I prefer BS lain out EEGGEG. TB is a must have if it's not a wild or foundation.

Parent names are a help to if I'm mushroom hunting and don't want a bloodline I've already got.

Stars like 4* are great too.

I try to do BS Tb * and any interesting colour genes. eg GEFEEG 8Tb 3* ee Ff Lp P2 And if it's a mushroom shettie I'll throw in the parents in case others don't want more of my lines.

Pricing no idea. I hang out around 8k to 15 k depending on what it is while throwing rare ones into auction and seeing what happens.