I see no problem with the rising prices of Pokémon tournaments in the grand scheme of things. As for how things have changed over the years, they've definitely gotten more expensive, but many people still participated because participants have enough money to cover the costs. Also, rising prices for tournaments make sense today considering that tournaments have been on a hiatus for two years because of COVID-19 and inflation occurred as a result of COVID-19, resulting in an increase of venue costs that The Pokémon Company has to cover. Albeit Pokémon is the highest-grossing media franchise of all time, they still don't want to invest in any programs that would result in them losing money. Thus, they are more likely to raise the tournament entry fees to cover the costs of the venue. However, because the rise in costs are very likely the result of inflation, the rising prices are likely to be temporary. As for having to pay a fee to enter the tournament in general, I see no problem with it.
Nothing is free in this world. If you want to attend any sort of event, it often requires you having to pay for it. If you're working and have a steady job, $70 shouldn't be too much money for any Pokémon player. Besides, at the Pokémon World Championships, Pokémon Trading Card Game players could potentially win $1,500-$25,000 in prize money and Video Game Championship players could potentially win $1,500-$10,000 in prize money depending on where they place in the tournament. People need to understand that competitive Pokémon isn't "fun;" it's a seasonal job. For many of the serious TCG and VGC players, world championship level competitive Pokémon is a career with a lot of money on the line. If $70 is too much for any Pokémon player and he or she isn't confident that he or she would earn enough Championship Points (CP) to advance to the Pokémon World Championships, then they have no business paying the money that they believe is too much trying to compete in the official tournaments.
Instead, video game players that prefer to play competitively but for fun are better off entering the competitions on battle simulators such as Pokémon Showdown or playing ranked battles on the Nintendo Switch and attempt to climb for the highest rank. TCG players are better off sticking to games at their local card shops. Those that are passionate about competitive Pokémon and confident in their abilities would do whatever it takes to win and don't care about any fees, as well as have the ability to financially support their goal beyond Pokémon. However, personally, I feel that if Pokémon is going to continue raising the entry fee prices for tournaments, then they could at least add more to the competitive scene, such as an official Singles championship tournament. Singles Pokémon is still, by far, the most popular way to play Pokémon and much like VCG styled Doubles, 3v3 Singles are also quick-paced and audience-friendly. It's the least Pokémon can do for us if we have to continue paying more money to enter their events.
