I want a CRM system which comes with low TCO
I totally understand the need for a low TCO. However, just asking for one might result in answers that look affordable but when evaluating them you might find they are not a fit, a complete fit, a partial fit, or not a fit requiring customization. The true measure of "Cost of Ownership" really comes down to how much of a fit can you get right out of the box. I recommend posting an addition to your question to state the kind of business you have and what your sales strategy is. If you have inside and outside sales people, or possibly reps, or maybe distributors. Describing how you go to market will help all of us give you a better answer than telling you to download the newest shiny object out there that is free.. but after you mention your needs you find out you need module X,Y, or Z and other costs. Feel free to email me or post it here and we'll all be able to make a better recommendation for you.
See bpm'online CRM. probably the lowest priced top CRM http://www.bpmonline.com/products/crm/features