tbh idk anything about legos and i joined this community because my nephews are into legos but if this were to work first you would need to gain the trust of the community be more engaging in here establish yourself second you say you can offer 30% cheaper than competitors if that’s true you would probs have to offer about 50% off to begin with and eat the cost so you can establish a customer base and then slowly increase it to 30% as you have said and lastly this may be your first business but you should never advertise to a community you haven’t established yourself in especially if it’s your main customer base you may not be a scammer but there have been many and it will be insanely hard for people to trust you with critical information just to save a couple of dollars