Vinyl siding costs, similar to the expense of other construction and home improvement products, vary from one visit to the home improvement store to another.
Sometimes the prices of consumer goods in the housing market--such as vinyl siding--rise or drop imperceptibly, and sometimes they fluctuate wildly on a daily basis.
Why is the price tag such an unpredictable factor when you're calculating the cost of repairing or replacing your vinyl siding?

• Availability.
  Wholesalers and retail outlets are both at the mercy of the manufacturer's ability to produce and deliver the siding.
  They can only sell what they have.
  Manufacturers are subject to a variety of floating factors that dictate how much siding crosses the parking lot on the way to the store.
  These include available materials, labor problems, down time in the production process and market demand.
  
• Vinyl costs in free market competition.
  If vinyl is selling at a specific amount in the lumber yard, the home improvement center had better come close to matching the price.
  It doesn't take long for consumers to begin flocking to the best prices.
  As retailers compete to sell siding, the prices invariably settle to about the same level in area establishments.
  
• Mark-ups count.
  As wholesale distributors buy direct from the manufacturer, the mark-ups begin.
  These brokers sell to retail outlets but add on their own costs and profit margins.
  How many times the vinyl changes hands determines the amount of mark-up over the manufacturer's original selling price.
  

Vinyl siding prices are dependent to a great degree on the availability of the siding and consumer demand for it.
Retailers need to make a profit on sales but can't be blamed for factors that are beyond their control.
Check several retailers when you're in the market for the best deal.