While the game is good, I wouldn't buy it only for the miniatures. The cultists and shoggoth are too small and aren't as good on details as other mythos monsters on the market.
The investigators would work if you didn't find a better sculpt. The map is a little abstract but beautifully illustrated, and would make a great board *if* you wanted to track where each character was in a Call of Cthulhu RPG.
Not cheap, but the Cthulhu Wars figures (no investigators) are the best quality for the price. They will have a KS in a few months. Sign up for their newsletter. Last two KS had a bonus item if you were on the newsletter before the KS began.