For a wet suit, a 7mm is the minimum. A farmer john style 7mm would be better, Yes, even in the summer. I dive Lake Champlain in Vermont, and even in late summer, bottom temps (around 110′ or so) are in the high 40′s. Wetsuits range from $150-$400

I dive a dry suit. with special undergarments. A dry suit will start at $800, and run into th high $3000 range with undergarment. Dry suits do require extra training.

As far as your BC and regulators, check local shops first. It’s really nice being able to have your gear serviced locally, rather than having to send it out by mail like you would for an internet purchase. A package should start around $600.

Then there’s the training. Basic open water will run you around $150 to $250.