Fact #1: the Turbob wasn't "impossible to find". It was carried by Sears, Service Merchandise, Montgomery Ward, JC Penney, and Radio Shack, which were all nationwide.
Fact #2: Mortal Kombat wouldn't have been a huge system seller, as few people would've been willing to pay $200 to play MK ($90 for the system, $50 for the game, $20 for a Tap, and $40 for a pair of 6-button controllers). That's mighty steep to get a game that wouldn't have been exclusive for any length of time, 90 days tops.