
Exactly, it's just Dojin is trying to marry his surrogate against their wishes. At the end of the day, Hye-sung has zero financial security. The only thing of value he owns is that rabbit toy from his mum, 19, no savings, no family support, being forced to not work, so he is now completely dependent on Dojin. Healthcare costs a fortunate, and Hyesung would need thousands to pay for the care associated with the pregnancy, birth, aftercare, and the long term after care if anything goes wrong during the pregnancy/birth potentially. He has no security that Dojin would cover any of these costs. Hye-sung can't even afford the scan photos or abortion fees himself. Surrogates generally get given an allowance, Hye-sung is just enjoying being able to have a warm bed, a stable supply of food, and being willingly treated to things like clothes and jewellery, he thinks it's a few months of this bubble, before he can leave that house and become independent again, as naive as that is.

Gullible indeed, although we understand this is influenced by his dad persecuting omegas, which is why he was in denial and behaved irresponsibly (not using heat medicine, trying to get the operation etc). There are going to end up together regardless, it's yaoi at the end of the day, and in the current Korean chapter there does seem to be some development, with Dojin becoming more aware of Hye-sung's background, Hye-sung is forced to rely on Dojin physically now, due to the pregnancy taking it's strain on his mental and physical health, it doesn't seem like love yet though. Hopefully there will be a chapter soon on Dojin taking Hye-sung to meet the Park family, it will show Dojin having to get a bit of courage and "lose face' in front of his siblings, seeing as he was so adamant that he would never go with an Omega, but it might be a good opportunity for Dojin to show more sincere affection towards Hye-sung, and for Hye-sung to maybe start seeing Dojin as someone to be a family with. It would also be an opportunity for Hye-sung to see a positive representation of what an Omega male can be, as Dojin's Omega dad (although he calls him his mum, which I always think is a bit odd), might be able to empower Hye-sung about his identity and pregnancy.

A surrogate mother is fine and they are taken care of during pregnancy. But this surrogacy is so transactional. This is blatant selling with a price on the child's head. That's why it's even illegal in some countries to do this. Some people make it into a career. Dojin is also no better since he doesn't have an actual plan for this child except for making Hyesun fall for him so they can be a happy family. It's a mess but we'll see.
Hyesung selling the baby is tipping the scale a bit. I like Hyesung and his personality but this decision to sell the baby is not something I can support. But I hope the story has an HE.