It is now becoming a 2 year investment, although I do ride at least a 600 most years so not a huge issue. As said above, it just depends how much you want it.
Edit: I hope I have not misinterpreted what you are saying, but I don't think it's all to do with "who wanted it enough".
This ignores, at least my experience, of not having known what audax was before august-sept of 2018 (or otherwise all those who recently discovered it, i.e. 'the next generation' as we've been referred to at all the recent audax events I've been to). All my research and queries were responded to with "never has PBP sold out before, but do a 200". So with not enough time to do anything more I registered for my first 200 in November 2018. Then, I created a Reddit account as I discovered it was a great way to communicate with other cyclists. It was just happenstance that another user saw my comment about doing a 200 in November and quickly deduced that I had not understood the rules correctly and if I wasn't doing the Lancashire Lights 200 in 3 days time I would miss my one and only chance to 'pre-qualify' for PBP. So I immediately booked a train to Blackpool from London and a B&B for two nights. I counted myself so fortunate, having achieved the 200 and have since dedicated all my spare time over the last few months to my new hobby in audaxing. Researching, spending a lot on new equipment, and completing two further events to date in 2019.
To write those off who didn't do a 600 as "not having wanted it enough" is unfair. We could just as easily say the same about those who only did a 600 but not a 1000.
I otherwise appreciate all the words of advice and recommendations for other events. It is not 1200km I wanted to do—I have done 9000km across Canada—it was the world's oldest cycling event at a time in my life where I have the availability and the health. Everything was aligned, I did what I was told to do and then bad luck hit. It was not that "I just didn't want it enough".