Totally agree on your last sentence. The villas there are relatively cheap, huge, well kept and an escape from the madness. We stayed in one of many villa groups around Champions Gate and would recommend the area to anyone.We were there 4 years ago, and again 18 months ago. Epcot has gotten horribly expensive. 4 years ago we could eat and drink our way around the world (only made it halfway before we ran out of steam lol) 18 months ago we just couldn't afford it.
Agree on magic Kingdom and Kennedy space center. Always worth checking the launch schedule before you go. We got to watch a space X Falcon go up and the booster come back down... well worth the price of the holiday on it's own!
Oh, and we always do villas. Much cheaper and far more relaxing.. plus you have your own pool and privacy as well.
In terms of cost, we have been twice and probably the same years as you. Don't underestimate the impact of the exchange rate. Like you, we noticed a big difference in costs between our first visit and second visit but when we looked back through our records we reckon the biggest difference is the exchange rate. The EU referendum was in 2016 and that had a major impact on the pound.