Both sets retail for £5.50 at current exchange rates. The rifle set comes with four guns, two copies of two designs, whilst the pistols come in packs of six-two copies of three designs. Price-wise these are a premium product, much like Evil Craft's Range. When buying these, remember that you are buying quality and design. There are plenty of cheaper alternatives, but none of them compare to the level of detail you are buying here.
The pistols, on the other hand, fit much better (tacked on for illustration). Being one handed weapons makes them far easier to fit, and don't look as oversized on normal-scaled models. These intricate pistols are perfect for sergeants, champions and lords of all flavours, as the designs scream chaos, but don't dedicate themselves to being overly mutated or run down. They are chaos at it's simplest, and that is good.
These weapons are a fantastic special weapon for your chaotic forces. Since you shouldn't need too many (unless you're playing a Chosen-heavy Abaddon list), the pricing should be less of an issue. For your money though you do get exceptional sculpts with examples of the highest quality on the market.