I'm a NJ diver and do about 50-60 dives a year here. My first wetsuit was a $25 garage sale special that I used for about 5 years, until I wanted to start going earlier and later in the season and was getting too cold. I went dry over 20 years ago and would never go back.
I have a DUI Norseman shell suit (similar to their TLS350). I have thick insulation for cold water, extra thick insulation (my mother-in-law made for me) for those January & April dives, and use regular thermal underwear for "warm" NJ dives in Aug & September. When I go to the Caribbean, I rent a wetsuit because it's less stuff to carry on a plane. I've tried a crushed neoprene drysuit, but felt like it was too thick and cumbersome and slowed me down.
When I bought my dry suit from my LDS, I was also looking at a Henderson Gold 7mm, and the price was about half of what I paid for my drysuit. Coming from a $25 garage sale wetsuit, it didn't make sense to buy a $700 wetsuit that still wouldn't keep me warm in April, November, December & January. (I draw the line at NJ diving in February & March)
Some of my dry suit friends will go wet in August & September. I'm just so comfortable in my drysuit, and so used to my buoyancy control, weighting, etc, I don't see the point in changing out for a few dives.
A few things:
I understand that you like the cold. But the NJ ocean is 40 degrees in April. With luck, it'll be 70 degrees by August. It'll still be high 50's in November. So, in a dry suit, you'll be able to extend your local diving by many months, versus using a wetsuit. Just remember, when you get back on the boat and the ocean is 55 degrees, the air can still be 40 degrees. You're not going to want to be walking around the deck of a dive boat in a wet neoprene suit then. The cold will literally suck the life out of your body.
Your LDS is suggesting you buy two wet suits? And you're not even certified yet? Unless I miss something, he's putting the carriage before the horse. I'd pick up a used 7mm wetsuit (or just rent) to get some diving experience in, then go shopping for a drysuit if you find that you need it. You might find you don't want to dive in NJ.