I don't know what wood chips cost ' for indoors smokers '
but Home Depo has them for the BBQ and they are the same and probably near you and much cheaper ;
http://www.homedepot.com/s/bbq%20wood%20chips?NCNI-5
all you have to do is not to use too many , and then seal the ' pot ' tightly and when the remaining wood chips go out and cool , store in a zip lock , perhaps in you
garage or similar if they then are very aromatic after some time in the HD zip lock bag
Ive done a lot of woodworking and used my own chips on grills etc
just use fruit wood and you will be find. the smoke does smell different i.e. cherry , apple but your smelling smoke and in the smoked item the wood
difference is less pronounced. Hickory is fairly strong smoke. Mesquite perhaps the strongest.