Simple Questions from new diver

[ilightyouup]

Thanks to all for the advice! My trip is one month from today and i've just booked 5 dives on the Sunny East End of Grand Cayman. One last question for you. My buddy is going through certification now and when he arrived at the LDC with Mask, Fins, and Snorkel newly purchased from Dick's sporting goods for $79 the DM said "no way" and made him purchase $200 worth of the same from him before he would let him in the pool. Is he getting taken for a ride? I got certified in GC with the same $79 equipment (Body Glove) and dove the East Wall 4 times. Am i being unsafe if i continue to use this equipment?