Out of any era, the EX era from 2003-2007 had the lowest production quantities. Pokemon was trying to revive the popularity of the hobby and they introduced a higher level of rarity, the EX Holo. Instead of the typical rate of 1 in 3 for holos, these were more intricate artworks with a complete holo pattern that extended to the edge of the card. These had a pull rate of only around 1 in 18 packs(2 per box). EX booster boxes range from about $60,000 on the low end up to $250,000. These are not only even more desirable than the WOTC era holos but are significantly more scarce.
PSA 10 EX HOLO!
These are limited to only 100 total boxes and will be released in waves of 10. The top hits include cards like the Umbreon($40k+), Espeon($35k+), Lugia($25k+), Celebi($25k+) and several other huge hits. Also, these boxes are unique in the sense that they have the highest floor value compared to the cost of any other series so far. The lowest possible value that you can pull from one of these is about $2000 based on current market values so the downside risk is very minimal.
