Hi M,
I infused 20 vanilla pods in a litre of OO for about 6 weeks (probably could speed that up a bit by heating the oil?). I then used it in soap (having strained thro' muslin) as 35% of the oils. I also added 1% styrax benzoin oil, so I can't be sure exactly what is giving the most scent, but it has a lovely vanilla toffee smell, and so far (about 3 days after making) it is a very pale creamy brown colour. This is the styrax benzoin that comes as a thick oily liquid.
If you don't want to use benzoin, you could try the infused OO in a small test batch, and let us know if the smell comes through on its own. If it does, then if you can get your vanilla pods cheap it's cheaper than using vanilla absolute.