My little 2 cents on this super interesting topic as a young pilot:

_When considering to buy an used ship, it's not only the purchasing price that is taken into account but also the resell value. How is it going to hold in the next years to come? No one knows but the increasing number of good sailplane manufacturers (Jonkers, Winward perf, LAK manufacturer, etc.) with excellent machines leaves me to believe this is going to drive prices down in the future.
_Having multiple racing classes is not going to drive growth but rather the opposite as the choice to race is based (for me at least) on whether I can have fun without too much risk. 18M planes theoretically out-glide 15M sailplanes and therefore seem to be more attractive. Open class is just too much of an hassle logistically speaking, it requires more skills and landing out is quite an adventure depending on the terrain. If I had to choose, I would go for the 18M as it is fun, fast and a good compromise between 15M and open-class.
_Sustainer/Motorized/pure? It's a touchy subject, flying with no engine is the purest form of gliding... However, having witnessed first hand my friends using the turbo to escape a land-out while I conceded my 'defeat' and landed-out for a very very long & frustrating retrieve, I must say I was envious of this little piece of engineering on their back! It's a nice fail-safe. Now, motorization is really the thing that takes it out of the crowd: you can go wherever you want, whenever you want. This is the purest form of liberty, which is what soaring is about.

All in all, as a young pilot who wants to learn and develop my skills as I age, here is what my plan would look like:
_Learn how to fly basic gliders (ASK-23/1-34/Pegasus/LS4) until being able to fly X-country on a regular basis - DONE
_Buy an used club glider with good performances (LS4? Pegasus? Discus?) and learn how to go further out (500km, 750km) building more and more experience on X-country flights. Start competing in Club contests. Unknown timeframe, several years for sure!
_Upon feeling okay (and after being checked by a CFI), transition to a high-performance sailplane with sustainer, making the transition to 15M class. This is where I would LOVE to fly a modified ASW27 FES as it is a good stepping stone to high performance competition.
_Ultimately, buy a motorized 18M ship (Ventus 2cM? ASH 26?) to go on soaring adventures, safaris, etc.
OR
_I could also stop at the 15M as performance is already amazing (Thank You B4 for all those inspiring videos!!!) and I would still be extremely satisfied flying those beautiful birds. I would just need this sustainer/motorization though.

That would be my plan, knowing that each step could take years... But it's like wine: the more you wait for a Grand Cru, the better it gets. But one should not wait too long otherwise you miss the golden period!

Now, this could explain the lack of interest for 27s: if I want to go up to 15M competition and stretch my limits, I need a sustainer that 27s don't have. Don't get me wrong, the ASW27 IS the most beautiful sailplane ever designed aesthetically and technically speaking. The best value for money also.. If it were to have a sustainer/FES/Jet/whatever, I would NOT hesitate for a second. However, it suffers from not having it and therefore could look less attractive than a Ventus 2bT (still beautiful, but less than the 27. Sorry Schempp-Hirth).

Again, my 2 cents. I would love to hear from other owners their buying process throughout their flying lives.. Extremely inspiring to see you guys with those amazing machines, thank you for showing us how it's done!

Cheers!