This is normal for them - I paid up front and waited 4+ months last year... when I ordered I was told the jet was ready, only needed paint and I would have it in 2 or 3 weeks!
That said taking the $ up front and making people wait doesn't seem to be slowing down their popularity. If they actually gave an accurate date at least you could make an informed decision.

In the end I was not happy with what I got and won't be ordering from them again.</p>