I know i should not feed the trolls, but i cannot resist so here it comes:
You assume the following:

• The solution that takes 10GB is done in 0 time or time much less than the Bloom Filter
• I do this for a boss who pays me to do it and wants me to work as cheap as possible
• It will take a lot of time to make the Bloom Filter solution

These assumptions are incorrect because of the following:

• Typing use DBI; takes about as much time as typing use Bloom::Filter
• As stated in the OP, i do this for fun & excercise
• using Bloom::Filter, implementing this will be a snap