Pfft. I'm constantly broke on x and y and I believe I've bought most everything I am going to. Especially since I looked at the items and I had unlocked everything there. But apparently I still have to go back to some regular shops on certain days and purchase some things that looked nice.... I must've missed this certain days.
o.O How do you not have money in the game I still bought everything in the clothes for both male and female twice plus items for the game such as repels and so forth. All the HM's and I still had alot of money left over. Then again I used the Prize Money O power sometimes and the Amulet Coin on my Froakie throughout the journey once I got it.