Selling items using the odd pricing strategy and not giving change

There's a trend among large retailers of using a marketing strategy called odd pricing, eg. $4.99, instead of $5. This is based on the psychological trickery of making a price more appealing. Muslim informal traders have now adopted this same strategy.

Firstly: Is this allowed, considering the origin and deceitful nature.

Secondly: These Muslim traders accept the full amount of $5. Unlike the large retailers, who give your change, the Muslim traders offer no change to the customer. This price is sometimes $199, and when accepting $200, no change is offered. Is this permissible? Surely, this is a form of stealing. At the very least, trickery.

When called out, they offer 'Urf as an excuse, saying this is the general usage in a community. However, the retailers who use this strategy gives the customer his due change. So it does not equate to the same.