I'd say get them. I really like the piggies for their texture and the color pay-off, especially if you use both in the same look. On my skin, Guise swatches as a very light silver and I have nothing that comes close to it. It is a nice color for a subtle smokey eye that will look stunning on pale skin, especially if you wear it with a vampy lip.
Deceit is much more burgundy than purple on me, with the purple coming more as a sheen whereas the base seems to be a true burgundy. IMO, it's rather unique and I don't think it looks like deep purple.
For reference, I'm NW20 (maybe closer to 15-18 during this time of the year), so the colors might look different on other complexions.
The only drawback is the smaller size, but piggies are usually the only product that I do not BU as I haven't finished any yet (except for perm colors). Happy shopping.