Needing a logo completely depends on what market you are pursuing.
If you want to charge as though you are a freelancer, to be hired by clients that are looking for a “cheaper solution” than hiring an established company, a logo may work against you. A logo makes you look like a company, which will make people to expect a higher level of service and market rate prices.
If you want to charge as a company, you WILL need a logo. A logo is an investment into image, which usually represents a commitment to build a long term presence. Prospective clients respond to your illustrated confidence in your long term presence, by a greater confidence in purchase, and a higher valuation of the work provided.
So the long and the short of it is this: if you want to charge below market rate, don’t get a logo. If you want to charge market rate, you need a proper brand, including a properly designed logo and web design.