www.cartridges2u.com have a Freephone 0800 number and
www.ink2u.co.uk have a normal 01 phone number that is free to call for anyone who has already paid a set monthly fee for the phone calls or who makes them using
www.voipcheap.co.uk at 0p per call. But your 0845 number costs 3p to 4p per minute depending on your customer's phone provider. Its only 3p per minute you say but if everyone took your line of reasoning these 01/02 inclusive calling plans would be worthless (as indeed they largely already are) and everyone would be paying £40 or £50 a quarter at least extra in phone calls to these 084 and 087 numbers (all 084 and 087 numbers are bad as far as we forum regulars are concerned).
So no sorry your change is not good enough either in an absolute sense or vs your competition who are using 0800 numbers or normal 01 and 02 phone numbers. But the fact that you used an 0871 number in the first place obviously suggests you can't be a very good businessman.
Are you sure you aren't a friend of redtreble or tripleeight? The line of reasoning in your posts seems really very similar to his way of thinking as he made a big deal of trying to suggest we think 0845 is perfectly ok when we most certainly do not.