Hi! Buying a preloved iPhone 12 for 18k with 128GB storage can be a good deal if the phone is in good condition and the battery health is still decent. The iPhone 12 is still a great device in 2024, as it has a powerful processor, good camera quality, and will continue to receive software updates for a few more years.
However, before making the purchase, make sure to check the phone thoroughly for any physical damages, screen burn-ins, or other issues. Also, check the battery health to ensure it can still hold a good charge.
Overall, if the phone is in good condition and meets your requirements, then buying a preloved iPhone 12 for 18k could be a good investment for your first iPhone experience. Just make sure to do your due diligence before making the purchase.