To find the right POS system for you, there is more than just the initial cost to consider. You want to look at the ease of use, both the initial cost and carrying cost (maintenance and/or monthly & yearly service contract fees), and whether or not the system can be programmed to work with any processor. This is important because if you purchase processing from the same sales office that you purchase your POS system from, they have you over a barrel. They can increase your processing costs right up to the point where it would be cheaper to get a new system than to pay their rates... and even then, if you lease the equipment and signed a long-term lease you may still be on the hook for it even if you don't use it. Always make sure you check the contract for early termination fees and return policies.
Talk to other business owners in the same industry to see how happy they are with both their machine and the customer service they get when they encounter problems with the equipment. The last thing you need is to be stuck with equipment that doesn't suit your business and is costing you a fortune.