Usually carpet is a relatively inexpensive improvement that can make a big different in a buyer's perception of your home. Do not expect to add the price of what you spend on new carpet to the asking price of your home - it is the type of improvement that may lead a buyer to choose your home over another. As some of the others have stated, there are definitely some inexpensive things that you may want to do (along with replacing your carpet) to prepare the home for sale.
It also may not hurt to have a professional home stager out for a consultation. The stager I use comes out to all of my listings and walks through the home with my clients, and makes a list of recommendations to prepare the home to be viewed by buyers. Usually she recommends things like cleaning, putting some personal items away, rearranging furniture, painting, cleaning or replacing carpet, planting flowers, installing fresh bark, etc. You can then do her recommendations yourself. You can also retain her services to assist in a partial of full staging.
Depending on what agent you select to list your home, many agents offer you a staging consultation with a pro as a part of their listing package.
If you want to call a great stager, I recommend Melinda with First Impresssions at 916-541-8181. That is who I use...
Forget about the "current market" and plan to sell your home. A home always presents well with fresh paint, new carpeting, eye catching landscaping etc
If you thisnk it is something that needs consideration, it will not escape the close scrutiny of a warchful buyer. So to not deal with the needed changes would be to work against yourself .......when trying to sell your property.
If you are serious about selling the home, do what needs to be done to sell it by making it irresistable to the buyer.
Make sure to get advice from a staging company or interior designer about what will be most appealing to buyers in today's market. Don't just go with what fits your taste. Your taste may be wonderful but you want neutral with widespread appeal.