Ratios to determine company's current purchasing power what are the parameters which will affect a company ability to buy a new product based on its current financial situation.  Is there any metrics or ratios which will tell the current company purchasing power?
You could probably get a very good idea of a company's ability to spend money - that is, make capital investments, develop new ventures etc. - by investing its balance sheet and develop both liquidity and leverage ratios. High liquidity with low leverage means that a company is probably not investing enough. Low liquidity with high leverage ratios would indicate a company has already invested heavily and is not in a position to undertake new ventures etc. 


Here is a good introduction to leverage ratios 
 Here is a good introduction to liquidity ratios