I just recently purchased 30 O-scale painted plastic sitting figures to put in my On30 passenger cars.  I ordered them through eBay from a Hong Kong company called WeHonest.   I was really skeptical about this transaction, but it turned out to be a good deal.   It took about three weeks coming from Hong Kong, but the figures came as advertised and at a good price.  The figures were approx. $27.00 and the shipping approx. $3.00 so it came to $30 for 30 figures.  They have a variety of figures in 'O' and others scales at affordable prices.  Check them out on eBay.