If you're on a thrifty budget, your best bet is this Topshop Mini Skirt. It's a great item, while not very pricey. Another nice option is this Missguided Mini Skirt. While the price is not too high, be sure that this item will become an excellent addition to your wardrobe. You may also want to look at this Express Mini Skirt. This item is not expensive either, but it will make a difference in your wardrobe.
If you're gonna splurge, then you absolutely must check out this No.21 Mini Skirt. This piece seems costly, but it's well worth it.