Wear something you don't mind giving away. I suggest old clothes, skirt, top, old bra and panties. Heels of course are required.
Here's 67,80€, 65 plus 2,80 in twenty cents coins. Leave any other money or credit cards here at home, but bring two bus tickets and a pair of scissors in your bag.
You'll be taking the bus and heading to the mall; there you will visit four shops.
In the first shop you'll be looking for a skirt. Ask a saleswoman for help. Tell her you're looking for a miniskirt and try on any skirt she suggests. Among them you must choose the shortest one and buy it. No matter how much it costs.
Exit the shop and go find a toilet. Once you're inside your cubicle use the scissors to cut up the skirt you're wearing. Wear your new skirt then.
Before leaving the toilet unclasp your bra, take it off and keep it in your hand.
Once you're back in the hallway throw the bra in a trashcan. I hope you didn't decide to wear a see through top.
Head to the second shop now. It has to be a lingerie shop - you're looking for a bra since you're missing one now. Ask the saleswoman to show you some sexy bras, tell her you need something to surprise your boyfriend. Try on every bra, mind though your budget is limited and you will have to make it last at least for a top and a pair of panties. Make your own choices now, you won't be coming back later. If you feel you could leave the bra behind, I suggest you do so.
Whether you did or did not purchase the bra it's time to go to the toilet again. This time take your panties off and cut them in tiny little pieces with your scissors.
Then calmly head to the third shop. You'll be buying a top now, one you can afford of course. Once again let a saleswoman fetch the tops for you. Tell her the boyfriend story again and that you're looking for something sexy, maybe see-through.