I have really mixed feelings about DENIX. I had a M16 for a very short time as I was really upset about all the trade-offs they had made. I am a very big M16 fan and wanted to add this to my collection. It cost 150 €, so not too expensive, but for 300 € you can get a good used Marushin or MGC ABS M16 which is much more realistic.
I also had a PPK pistol which had some trade-offs as well, but it was still nice looking and good feeling. The price was 50 € so not too much. A nice and legal blank pistol or a modelgun will be at least three to four times this price.
As a display model the PPK is good enough.