Why does it cost so much to collect Pokemon cards?

Although Ultra Prism has only been out for a week, I've already invested $1,000 into the set. Why is it so expensive to collect Pokemon cards? For me, the goal is to always complete newly released sets as quickly as possible, merely for the satisfaction of completing the set. What I do is I buy 2 sealed booster boxes, and all other sealed products released, like Elite Trainer Boxes and blister packs, then I finish the set by buying singles. I am happy to say that I have already completed the Ultra Prism set, but it seems like with each new set in the Pokemon TCG, I have to spend more and more money! Between sealed products and singles, I spent around $1,000. There is no possible way that children or those not working full time can afford to complete sets like this! While I enjoy collecting large sets like Ultra Prism, with 173 total cards, I would be much happier if Pokemon removed GX Rainbow Rares from sets, or, if they made several regular GX in a set, then only made a few cards available as GX Full Art or GX Rainbow Rare. Of course, I could save a lot of money if I waited until sets like this were out of the Standard Format, but it isn't as fun to collect when the set is older.

As I'm getting more and more involved in the competitive TCG, my goal to collect as many cards as possible is decreasing, I would much rather just buy the cards I need for a deck individually, or only buy booster boxes to get what I need. While it is a cool feeling going to a retail store and picking up all of the collection boxes or blister packs in stock, most times, the promo cards included in these products are either reprints from regular sets, or just aren't that good in the TCG. That got me thinking, I wonder what other collectors and players of the Pokemon TCG do to complete a set or to get cards they need, do they open sealed products, or do they just buy what they need individually.

My motto when it comes to buying singles cards is to check several online retailers as well as eBay and TCGPlayer to find the cheapest prices I can for each individual card, since I'm not sending my cards in to get graded, I don't necessarily need to see the exact condition of the card I'm buying, just having the near-mint designation is fine. While most retailers change their prices daily to stay competitive, I still find it best to search around, it is almost a guarantee that no one site will have the cheapest prices for every card you're looking for.

So this brings me to my question, what do you spend to maintain your Pokemon card collecting hobby? Do you try and complete sets when you're collecting, do you just buy your favorite Pokemon, or do you solely collect the cards you need for a certain deck? Lately I've been playing the online game a ton, mainly because the cards are cheaper to purchase, and you can quickly re-use the same card in multiple decks without having to build the deck again. For a hobby that seems to get more expensive with every new set, I'm all about trying to be frugal and save where I can, but still enjoy the hobby I've been doing since I was a kid.