We do this all the time, they have a buying agreement and we install it for them. Its just part of the business, especially if you are working for a retailer; they are always trying to work a buying agreement angle for profit.
1-You don’t have warranty their material, and they understand this or should. Make sure they do understand in your proposal and contract just incase they forget.
2- Add a little extra labor for handling their gear to cover your overhead, because when they say “we furnish” they mean in a truck to the site, and “you unload”. If you use a 1.5/h labor unit on a contactor, bump it up to 1.6/hour or 1.7/h if the conditions warrant it.
A variation on this is they will have a national account that you have to buy from, and then you get to warranty parts from a vendor you don’t know and who is VERY unresponsive. I just did an OfficeMax, and REXEL had the national account for the fixtures, and worked me over pretty well. My local vendor will handle any kind of shipping damage, while an out of town national account vender will just make you buy new fixtures at your expense laugh about it.
[This message has been edited by ITO (edited 01-13-2007).]