We had a situation earlier this week where a potential competitor started to use the name of a client’s service for a similar offering. Fortunately the client had trademarked it last year and we were able to politely bring this to their attention.
There are inexpensive ways to file for a trademark, the direct application fee is $325 and you can search for free on http://www.uspto.gov/ as well as use domain name as a proxy with tools like http://domaingroovy.com/
These legal services will check more and charge you $130-$500 for a search:
A name audit (see for example http://www.brighternaming.com/Name_Audits.html at $300 ) by a naming firm can be extremely cost effective at helping you prevent problems with a name that you have chosen. If you pick the product name to equal the company name then you only have to spend marketing effort to get one name into a prospect’s awareness. That’s probably the most cost effective thing that you can do, along with putting a TM on it right away which signals your intent to register at no cost.
I think it’s worth spending a small amount of money to get feedback from a naming firm on potential problems with your name before you commit to it. In particular if folks cannot spell your name when they hear it then your ability to leverage word of mouth will be lower.
Net net I would make my product name the same as the company name, get some advice on potential problems (note this is not a 10K or 50K “Branding study” but a few hundred dollars for an audit) and at least TM it if not register it.