Gen 1+/2 are fine for use with airsoft, the biggest issue is quality control some units are outstanding some are beyond useless. The biggest issue is the price in Canada is stupid and due to ITAR getting one from the US is marginal. They are not generally restricted but lots of places will not ship out of the lower 48.
Gen 1 and a lot of 2's are best on moonlit or partial moon nights, to avoid use of the IR. At airsoft ranges they are fine, and they will pickup anyone dumb enough to cross open ground.
But at 1000 + for decent gen 2 and several 1000 for a good gen 3 look at your priorities how often do you play at night. Is that much for an NV really worth it. If you have other uses for one then maybe it would worth the money, but for my money I do fine with a Gen 1+, I got a good quality unit before ITAR, I have looked at 2 others since and both were much worse quality.
Optic size and the lowest magnification matters for gen 1 and 2. A good scope with a 40 sized optic and 1 to 1.5 mag may be a better choice than a head mounted unit.