We rent ALL the time with our business travel
Check a lot of companies. Make SURE you get unlimited mileage and a lot of places charge a drop off fee which is where the big fees are incurred.
Example.. Alamo usuallly has a big drop fee.
I go directly to the car sites and I also use Southwest.com because I buy a lot of tickets on that site. Southwest's site will pop all the companies up with pricing for you.
It is alwasy cheaper to drop it off where you picked it up. DON'T buy the extra insurance. If you have regular car insurance which you should be law, you are already covered and the extra is a waste of $$.
Many of them have long term deals as well. ASK for the best deal.