Plexi glass is too soft for degu teeth! Degu's are very strong and can chew a hole in plexi glass. If you want, you can get good cages on Marktplaats.nl or zooplus.nl (or .co.uk) for example.
On Marktplaats (for the Netherlands) you can search on 'chinchilla'. With this request, you will get a lot of suitable cages. Building your own cage is most of the time not cheaper then buying one.
On degutopia.co.uk you can find a cage calculator. Here you can put the measurements of the cage in the calculator and it will calculate how many animals can be held in the cage.
: i was wondering if u could make a Degu cage out of flexi
: glass and put a screen top on it?