I too was sucked into buying a spyder clone (game face vexor kit) for £100 from e-bay (when gun trade was allowed) used it once on a public day and found I had a small advantage over the rental inferno's.
The next game I took it too was a walk on. I felt ashamed, needless to say I extended my overdraft and purchased an impulse vision. Sold the Game face kit for £40 (lost £60) and learned a lesson.
On the subject of the Ion, I have one as my back-up marker and they rip!!
Moral of the story:
Dont waste £50 - £100 on a cheap spyder, when you can invest £180 into an Ion and feel that you can compete with other players.
Believe me, within a few weeks you will move on to the walk-on scene!!
Dave