Do you know that Argentine boa constrictor is listed under CITES Appendix I? Do you know how hard to purchase or how expensive an Argentine boa constrictor is?
If you read my post then you would see that captive bred specimens are appendix II. I used to work for a marine laboratory that does sea turtle rehab. There is only one farm in the world that has bred them to the 2nd generation in captivity, and they reportedly sell to local markets (Cayman Islands) due to export restrictions. That boa is bred all over.