nambrot
The groove is relatively expensive because it is custom designed and built. The other IR-Pens are retro fitted devices (uv texter and UV light source) or whiteboard markers.
The are bound by the device/pen body they are retrofitting. If a AAA can't fit, it can't fit.
I can confidently say that
all the IR-Pen sellers on this forum sell an exceptionally high quality product for a very realistic price. It takes me 1hr+ to build an IR-Pen or I can buy one for $9.95 - $29.95. (I value 1 hour of my time as worth alot more to me that).
If you are on a budget I suggets you make your own IR-Pen, will help you learn more about Ir and the project too.
benpaddlejones
