Just an update that I completed this transfer today from AEP to EZE. Landed in AEP on LATAM from Puerto Iguazu at 12:42. I had checked a bag, and collected my bag and had my ticket on Tienda Leon for the transfer by 13:15. The buses leave AEP for EZE every hour, on the hour. Price was 580 ARS, which is $9.70 USD. Private transfers with Tienda Leon were 1,800 ARS. My bus left just before 14:00. The bus ride was comfortable - air con, reclining seats, USB outlets. We arrived at EZE at 15:15 after a stop in downtown to drop off/pick up passengers. Traffic wasn't an issue