Just an FYI, the Recurring Nightmares pack that was just released would give you all the figures and tiles from 1E base set for $50. It's also worth noting that the investigators and tiles have been given minor updates so that they fully match 2E stylistically (no "line of sight" dots, investigators have grey base, indoor/outdoor room label borders are updated), if that kind of thing matters to you.

I actually just picked up the Suppressed Memories tile pack, and the tiles are all reprinted to match 2E standards, meaning there are no "line of sight" dots and the tile labels have the newer borders. Going through them, both Rooftop and Spruce Grove have the blueish "Outdoor" borders, so I believe that the conversion kit instructions are a misprint.