I think a new "low budget two seater" is not really existing. At the "low end" of the production two-seat gliders, you have:

PW-6U (http://www.szdjezow.com.pl/) - not sure it is still in production, relatively low performance, good for spin training.

Perkoz (http://szd.com.pl/fr/products/szd-54-2-perkoz) - in production, good performance, good for spin training, adaptable for uncertifed hand controls.

ASK-21 (https://www.alexander-schleicher.de/...gzeuge/ask-21/) - in production, relatively low performance, spin training only with special mod, adaptable for certified hand controls.

DG-1001 Club (https://www.dg-flugzeugbau.de/en/air...01/dg-1001club) - in production, good performance, good for spin training.