If I could get my hands on an AFM for around $4-5k surely I'd save money than spend it on a restored one?
Of course mate, but who did you plan on doing the resto? Yourself or a third party? You can save dollars as a DIY, but it is a lot of time and effort for a full on ground up resto. And if you plan on using a commercial restorer, you know they have to add their slice to the overall cost. I'd estimate around 5k in parts and labour for a full on ground up resto with a new playfield and cab decals/ramps/plastics et al.
Out of interest what are these going for I good nick? $7ish?
Sounds about right, they are few and far between onsite anymore and container imports are guaranteed to nearly always need a new playfield/cab decals.