Hi Max,
I didn't realize they would be that expensive, Ouch!!!, but yes spending $200+ $$$$ on a flattener for that scope is definitly a waste so will save my hard earn't cash for an OTA worthy of it.
As a side, I bought the ST80 with the guide camera for guiding but figured I would have a crack at imaging through it as well seeing it was there (I am still relatively new to the sport of AP so slowly building up the gear and making the most of what I have at the time).
In the mean time I guess I can always crop down the image edges where the curvature is noticable untill a better OTA is an option.
Thanks for the feedback
Cheers
Anthony