I have talked with one person who bought VIP HTP for 1B, and several other people who are considering to buy the service. Most of them think the price is justified, because they are "spending 1B to buy a 22 all stat pendant". Next, I pointed out to them that: Normal HTP only has 6-8 stats clean. There is a VERY small chance that you can get godly HTPs with up to 13 stats clean. Most likely this won't happen in one HTP service. If you "egg" the HTP with a Nine Spirit's egg (through a quest), then you get +15 all stats on the HTP. That's how the 21-28 stats HTP are made. Each character can only egg 1 pendant, ever. If you egg the HTP you bought, you cannot egg any other HTPs that you get later, even if they may have better clean stats. Some of them said they didn't know it, and they will definitely not spend 800M-1B on HTP service after being informed. I myself think the HTP service is not worth 800M-1B. If you want to reach maximum potential on your character, you should not just egg a normal HTP, and should wait for a 13 stat clean one instead. In this case, you are most likely spending 800M-1B on a 6-8 stat pendant, which is barely better than a 300M 5 stat deputy star. Of course, the buyers may have different opinions. They may be fine with a 21-23 stat HTP as their end-game pendant, or they may think the "cool factor" of HTP is worth 1B, or they may be very rich and are willing to spend extra 700M for 1-3 more stats. I am totally fine with selling HTP service under these circumstances. What I think is NOT fine: The buyer thinks he / she is paying 1B for a 22-stat egged HTP now, and plans to egg more pendants after getting godly ones when he / she can HT. In this case, I think the sellers definitely have a responsibility to explain the 1-egg-per-character constraint to the buyer, even if the buyer may not want to buy after being informed. Some people may disagree with me and think it's the buyer's responsibility to do research and get informed. Either way, please vote above Edit: the 1-egg-per-character constraint may be changed in the future. Here is the feedback thread discussing it: https://royals.ms/forum/threads/nine-spirit-egg.111776/
I think it doesn't take much effort to say "Hey, you're paying 1B for a potentially shitty HTP that may have all states +6 up to +13, and egging it gives you +21 up to +28. This is for 1b!" Some players are really new to MapleStory as a whole, or they've never went to/bought HTP services in official MapleStory before, so give them a benefit of doubts.
I can only speak for myself, I always try to be transparent about these things, in my selling thread under the faq section it states that you can only do the quest to hatch an egg once per character. I always try to tell buyers that the pendants are 6-13 stat clean 6-8 is before godly system and that its very unlikely that they get anything above that. The service me and my friends provide is for people who might not have enough hp or even intrest in running horntail everyday to get a godly pendant its simply there for people who want 21+ all stat pendant. Theres also other benefits to running with someone who is providing a service. The run will most likely be faster and safer than most other, they might be able to get you through ht without meeting the hp requirement and ofc the buyer will be 1st to loot egg and htp which is not always the case if you run with a group of friends. I think that if youre buying a htp service or any other service for that matter you should ask questions before deciding. I think that many people will just assume that the buyer knows what he is getting if he has no questions.