You purchased an item on credit. As long as you do not inform other buyers that you have purchased it on credit, it will not be permissible for you to sell it at a profit or at cost (if mention of the cost price is made at the time of sale). Instead, you should inform them that you purchased the item on credit. In so doing, it will be permissible for you to sell it at cost or at a profit. However, if you do not make any mention of your cost prices, it will be permissible for you to sell it at whatever price you wish. You purchased a cloth for R100. Thereafter, you had it dyed at a cost of R4. Alternatively, you had it washed or sewn for R4. It will now be understood that you acquired it for R104. It will now be permissible for you to mention its cost price as being R104 and thereafter to make your profit on this amount. However, you should not say that you purchased it for R104. Instead, you should say that it landed you at R104 so that it is not regarded as a lie. You purchased a goat for R100. You kept it with you for one month and it cost you R10 to feed it in this one month. It will be permissible for you to quote the cost price as being R110, and sell it at a profit accordingly. However, if this goat produces milk, you will have to subtract that amount accordingly as well, e.g. if it cost you R10 to feed this goat and it produced milk to the value of R5, you will have to subtract this amount from the R10 and say that this goat landed you at R105.