Just been in B&Q and got a pack of five Jig Saw blades, (one 24T ali & 4 wood of different types) for a quid.
Seen them in fancy packs at around 7-8 quid for two. Reckon even if I destroy the ali one cutting up the thin sheet I'm cutting it will be a bargain.
Oh and I bought more than one pack just in case.

I got 25 metal cutting blades off ebay for £6

I didn't get on with ali blades to cut my sheets at all... just torn the metal and made a nasty noise!

Had much more success with 1mm blades in a grinder. (But for goodness sake wear proper protection!).

Even the grinder leaves an edge that needs cleaning up, best of all was a nice set of 'snap-on' tin snips I was lent..... made the job easy and no cleaning up the edge afterwards either!

Cheers,
James

False economy buy Bosch extra fine blades