I have also been multiple times with kids. I always get the park hopper plus. for two reasons.
1. If I am shelling out that kind of money I am going to spend the extra $100 per ticket to not only be able to go to another park if say I only spend 1/2 my day in Animal Kingdom and want to go see the end of night fire works at epcot etc.
2. with the extra per ticket can spend a day at the water parks and its i:ncluded!
everyone is different but I will always find a way to save a few dollars in order to get the best ticket that allows for the most options. Last visit (Jan 2017) we stayed at a place that had free bus couple times a day and saved $20 per day in parking. lots of little tricks to save a few bucks.
in regard to tickets I also disagree. I ended up buying direct from Disney as they had a deal specific to Canadians BUT... I bought my Universal tickets though a 3rd party with NO ISSUES. lots of them are very reputable.
can always send me a PM if you like a love helping plan trips to FLA. and I've been enough times now I can give you some good tips on how to have a blast and save some of money