If you're looking to make 15-20k each year you'll need to shoot around 20-25 weddings at your current price point in addition to your hockey league contract. In addition to full time work this is a MASSIVE committment for not much return. 20 weddings is so much more than just 20 SAturdays of shooting each year, it's also 20 Mondays editing photos, 20 Tuesday nights meeting couples leading up to their wedding, 40 Wednesdays nights meeting those who book you and those who don't, 20 Thursdays nights updating your website and doing the neccessary social marketing to ensure these jobs keep rolling in, 10 Friday nights doing the admin the goes along with running a business. This will seriously take over your life, and for what? $15,000? No, wait, take $5k off that in taxes. Now take another $5k off in equipment costs, LR and Photoshop upgrades, website and a myriad of other costs. After totally busting your balls and pushing you and your wife to the limit (especially with a young child), you're walking away with maybe $5k in the bank if you're lucky.
Ignore what the 'togs in your area are charging. Work out what price you need to charge to make it worth your while, if you're unable to get people to pay that price then walk away. $600 per wedding is no where near enough to make it viable IMO.