I made this deck to prove to someone that Angel Arena is a good card. Admittedly it's part of a combo - but still...
Essentially, Motivation, Oracle May and Eureka are already excellent combo pieces, but with the ability to cycle a quarter of your deck for 10 credits (remember that you've already drawn through the first bit) is huge. You cycle a bit, find something you want (say Alpha) and then play a Eureka on to it, bam, free things. Even better is if you can The Toolbox early.
Test Run can be used to force things onto the top of your deck for Eureka! - Scavenge is an option to do this as well - but by the same token, that combo doesn't work UNLESS you have the Test Run - whereas the Eureka! works without, just as long as you know what you want is on top of the deck. (Which is usually done with Motivation or Angel Arena - and not Test Run - at least in initial playtesting.)
As to why I'm using Alpha - it's a high cost thing that is made 0 cost by Eureka!. It's then made effective with the addition of The Personal Touch. I saw someone do it to a Ninja - and you know what - it works here as well. They'd better be triple ICEing - otherwise you can just slap Knight down and crack skulls. If it's too big for Knight, then D4v1d.
Considering I have 16 events that are all paid events, I do believe personally that Prepaid is viable, and a really good thing. Hell, even just the overpowered Dirty Laundry / Sure Gambles are good. Other economy to be made through Aesopsing redundant things, like a dead Cache / Imp / D4vid, or a Same Old Thing you don't need, or a spare Motivation. (Because Motivation isn't unique...)
Remember, this isn't supposed to be tier 1 - it's just a bit of fun. It's a deck that works - I've made sure of that - and there will be updates as I test more - but for now - it's just some fun jank that (kinda) works - and it involves Angel Arena - so to my mate who says it sucks - you suck. Nyuk Nyuk Nyuk.
(As always, comments are appreciated. This isn't a finalised product yet - of course!)