If you make your decisions solely on price then go with the cheapest. However, there are many other considerations that you might want to consider. Things like:
- responsiveness of working/buying from someone on your own side of the planet so you don't have to wait 24 hours for a response to a question (this is the worst thing about cs-cart support). And while they say they respond 7 days a week, that has not been my experience.
- Possibly other options sold with the cart from a reseller. Hosting discounts, free installation, marketing support, etc. This will vary from reseller to reseller.
- The reseller is someone you have or want to develop a long term business relationship with or they have other products that you want to purchase at the same time, possibly for even further savings.
- Supporting someone who gives you free advise here on the forums above and beyond what the vendor supplies.
But since your whole focus seems to be “cheapest” then you will be making a single-minded business decision which could end up costing you more in the long term.
Note that resellers are restricted whereby they cannot sell for less than a 20% discount off of the current retail price. Note also that a reseller purchases licenses in bulk (usually 10 or more at a time) and this is why they get a discount and can then pass that savings on to you. But they are fronting $$ for bulk license purchases.
When you purchase from a reseller just make sure that your purchase will transfer the license to you. Normally this will mean that cs-cart will send you additional info to have you agree to their terms and conditions and license agreement and will probably issue you a different license key from what the reseller originally gave you. If you do not receive this, then you do not own the license you paid for. You are using a license owned by the reseller which is NOT a good thing in most cases.