Ives,
What everybody else says, above, also:
If you're really only going to work with wood, you don't actually want needle files at all - even cheap n nasties will clog up with sawdust about every fifth stroke and drive you potty (please don't ask how I know this!).
If there's one near you, pay a visit to a local modelling shop (aircraft, boats, trains, etc) and if you can afford it, get a set of Xacto modeller's rasps. They're just like big rasps in terms of their cut & pattern ("teeth"), but much smaller physically, pretty much the same length as needle files. These are not cheap but certainly cheaper than a set of Valorbe or similar decent Swiss files.
Also: And/or keep your eyes open while wandering round B&Q, other DIY Emporia, market stalls, etc. You'll be looking out for a set of Warding files (usually in some little plastic wallet). Their teeth are not so fine cut as needle files (and they're a lot cheaper than all but the cheapest needle files) but will do a pretty good job on wood.
I use both the above on my aircraft modelling sometimes, working with balsa, ply, liteply, beech, oak, and GRP, etc. Whilst the tougher/harder the material takes longer to work to final size (of course) I still have a many years old set of Xacto modeller's rasps, plus a set of CK Warding files that I bought cheap off a market stall and both sets are still doing a good job.
And if you do go this route, do yourself 1 more favour - buy a small wooden brush with brass spines, as used for cleaning suede shoes. Brilliant for clearing all the gunge out of the file teeth.
Cheers
AES
