Go to auction sites like Gunbroker and Auction Arms (the biggies) and on-line sellers like Bud's Guns and CDNN to check prices. Add shipping and transfer fees to whatever savings you think you are getting.
I'm not trying to change your relative's mind, but I wonder if they have shot other calibers before deciding on the .380. My (limited) experience has been that there is a reason behind choosing that caliber that uasually does not involve having 1) tried it out first and 2) not trying any other calibers/platforms either.
Other than general officers not many folks OC a .380.