Currently, Combo Bases are a bit... odd. Not only are they mostly borderline worthless, no one really wants to breed for them because it's so incredibly demoralizing. The chances of them passing are absurdly low, it's been estimated at a mere 2% via scries, no matter the factors used, and currently, even selling bred combo bases is a pain in the ass. Most are worth at most 10GB (though usually worth around 3-5), with the most expensive bases being the June Combo Bases, which aren't even bought at the prices they're listed at, they're just so high because it's impossible to breed them.

"Jester, how are you going to fix them?" Simple. Stay with me, alright? It's a three step process.

1. Increase the rates of combo bases spawning from breedings of the Combo x Any Factor. For example, a Hellebore x Goldenrod breeding would have a 3% (or maybe 4%) chance for Hellebore, rather than the 2% chance it has currently, which is identical to a Lilac x Goldenrod breeding.

2. Increase rates of the Combo x the Combo breedings. This would mean a Hellebore x Hellebore breeding would be a 4% chance for Hellebore, rather than the same 2% chance it currently is.

3. Make Combo Bases Passable at a reduced rate.

Wait, what? Let's expand on 3 a bit. As seen with hybrid bases, making rare and hard to obtain bases passable usually doesn't devalue them all that much. Kimanjano and Mandarin still sell for a good 25-30GB, on average, and they have mechanics that increase their pass rate in certain breedings, and have a reduced pass rate in all others. This is what I would want Combo Bases to become. To give an example, let's go back to breeding Hellebore. There would be four methods to be a Hellebore breeder:
1. Having a Lilac King and breeding to Goldenrod and Udara Lionesses, for a 2% chance at spawning Hellebore cubs.
2. Having a Hellebore King and breeding to Lilac, Goldenrod, and Udara Lionesses, for a 3% chance at spawning Hellebore cubs.
3. Having a Hellebore King and breeding to other Hellebore Lionesses, for a 4% chance at Hellebore cubs
4. Having a Hellebore King and mass breeding to non-factor lionesses, for a 0.5% to 1% chance to produce Hellebore depending on the lioness's genetic rarity label. Just like Kimanjano and Mandarin function (confirmed to be half of the rate of other specials on the hybrid wiki page).

It's also rather annoying that a lot of combos can't reliably fail into some of their factors when you attempt to breed them with certain combinations, or when you're mass breeding them. This makes it hard to sustain combo breeding, as you'll end up eventually always having to buy factors, for example, Qahir x Qahir cannot fail into anything that is useable for the combo, other than Qahir, the same can be said for Arabica. Combos should have an increased chance to fail into their factors, and also have a chance to spontaneously generate a common, uncommon, or rare factor from the breeding, similar to how Albino can randomly appear from any breeding. This would only apply to non-special factors, Special factors would still need a parent with the base to appear.

Adding in to say the Combo Base roll should roll before the special base pass rate, as it's annoying that potential combo rolls can get blocked by specials in the breeding passing.

Feel free to let me know your thoughts below! If you No Support, be sure to let me know why. While I understand a lot of you may be against the changing of combo bases, I believe making them passable naturally will, if anything, help their incredibly low values and make breeding them far more accessible. Value isn't just determined by rarity, but also by the demand. Currently, there is very little demand to breed combo bases solely because of the way they function, so I feel addressing these functions might make the popularity of combo bases go up, and, in turn, their value as well. Thank you for reading!

EDIT: Adding a bit of reasoning for Number 3 - it's because currently, every other combo trait in game works like this, where the traits that make them need to be bred and, from there, the traits can be passed down either normally (in the case of Royal Mane & Mane Colors), or at a low rate, like Sectoral Eyes. Combo Markings in Wolvden also work identically to this as well, where once they're bred they can be passed down like any other markings. While I think allowing combo bases to pass identically to other specials would flood the market after a few months, I think a reduced rate equal to Kimanjano and Mandarin would help bring value back and alleviate some of the pain associated with combo breeding.

ADDING MORE
I also think Combos should have a higher chance to fail into their factors than any other common/uncommon/rare, similar to how Albino lions have an elevated chance to pass Albino. More detail on this has been added above.