Something different today as I got curious about matte topcoats and how they worked. While I was out I picked up 3 different types in order to see which one was the best. The first one was £1 from PRIMARK and their P.S. collection of beauty products. The bottle contains 7ml of polish, making it the cheapest of the three I bought at 14.3p per ml, great for us students! The next to were both bought from superdrug, the BARRY M matte topcoat and the COLLECTION 2000 equivalent. The BARRY M polish contains the most polish, with the bottle containing 10ml, but costing £2.99 is about 30p per ml. The COLLECTION 2000 also set me back £2.99 and contains only 8ml, making it the most expensive at 37.3p per ml.
So cost wise the PRIMARK polish is the cheapest, but the bargain price may not account for the quality of how well it works.