I would even argue that for by far most people, the registration cost will not be the limiting factor - other components of the trip would likely be (unless they are local to Stockholm, maybe). The travel to Stockholm alone will outweigh this fee by a factor of 2, maybe 4 for most, and a week of accommodation with the remaining dinners will probably set you back at least the same amount (if you go very low budget).
Those estimates are way off. Most of our volunteer base is in Europe, where flight costs are typically below $100; you can find accomodation in the immediate vicinity of the conference for $200 (and you can probably go way cheaper with hostels, or by being in a more distant part of the city); if you actually want to go very low budget and skip on restaurants / pubs / etc, food costs are minimal (and obviously people do need to eat outside of Stockholm as well, so it's not really an extra spending). So the conference fee would be about half of your total costs.
There are two ways that our movement can try to address this hurdle: one way would be to reduce the price even further for everyone, the other is to provide help for some people to overcome all these financial hurdles. I personally prefer that we spend more on scholarships (travel, accommodation and registration) rather than even further subsidizing the registration fee for all other participants.
So are we actually spending more on scholarships?
There is no consistent reporting on scholarships (nor any other aspect of Wikimania for that matter) but some wiki archeology gives:
- 2012: 87 full + 47 partial per 
- 2013: 62 full + 18 partial (which apparently somehow adds up to 86...) per 
- 2014: 109 per 
- 2015: 110 per 
- 2016: 88 full + 35 partial + 6 additional (whatever that means) per  ( claims 99 full)
- 2017: 81 full + 17 partial per 
- 2018: 125 full + 16 partial per 
- 2019: 96 full + 20 partial per 
So it seems like the higher price of the conference was indeed offset somewhat by a slightly higher number of scholarships in 2018, but that is not the case for 2019. (Granted this is WMF only, and a significant part of scholarships tend to come from affiliates, but it's even harder to find data on that.)