For the NPC commenting: Current cost with agent is about 6k baht to get in if it's from a denial entry, or 4k baht if you don't have a recent denial entry. Multiple agents offer such services including the agency owning this FB group (name on banner above). It's profitable to reject entry so that most will use agent to get in. You can also get in at border with agent. Agents work with different immigration officers. The officer wait for you at the gate and he's/she's the one stamping your passport, that's why it's guaranteed entry.
I used SR Services on LINE app last December to get in at BKK airport. Was 6k baht because I got denied entry in Nong Khai. Thai Visa Center also do it. They are the owner of this FB group (their name is on the banner at the top of the page).
Current cost with agent is about 6k baht to get in if it's from a denial entry, or 4k baht if you don't have a recent denial entry. Ignore all comments about you not getting in, they are NPC and don't understand that they want people to use agent as much as possible, as it's financially good for immigration officer too.