I've not had that email, although I did look at their bundle offer.  Never, ever click a link if you're not sure! 

Do you actually need it?

What a silly question 
Need/want?  Want/need??   

I've decided against it as after a bit more research, I've read that the pins that hold the needle plate on are prone to breaking, and impossible to find any replacements, even Helen Howes has given up trying to source any.  And of course, this machine's pins are partly broken.

I had the half price email from Jaycotts this morning too 

Envious?  Moi?  Hell, yes!!

Have fun with it!!

@HenriettaMaria I looked up the hex cardi - it looks great.  If only I could crochet, well I can a bit, but not well enough to make that!

I have a "selection box" of different types of needles, so take out and use the appropriate one for the fabric each time, then put it back in.  I, as most people might guess, only replace them when they break - works fine for me!   

Over a week later, and it's still hanging on the back of my sewing room door with a few clips in it - I still can't decide if I'll be able to do a good enough job!  My current plan is to cut off and re-make the front edges... possibly...

If it works ok sometimes, then you shouldn't need to adjust the tension.  Working one day and not the next suggests it's not the adjustments or a mechanical issue, but more than likely electrical.  Or did you mean it it does work, but doesn't sew very nicely?